Merge dl145s.mysql.com:/data/bk/team_tree_merge/CLEAN/mysql-5.0

into  dl145s.mysql.com:/data/bk/team_tree_merge/MERGE/mysql-5.0-opt


sql/sql_parse.cc:
  Auto merged
sql/sql_select.cc:
  Auto merged

16 files changed, 649 insertions, 269 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 96b20d0f0bb..c3b950bc32b 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -3746,13 +3746,48 @@ Item_equal *Item_field::find_item_equal(COND_EQUAL *cond_equal)
 
 
 /*
+  Check whether a field can be substituted by an equal item
+
+  SYNOPSIS
+    equal_fields_propagator()
+      arg - *arg != NULL <-> the field is in the context where
+            substitution for an equal item is valid
+   
+  DESCRIPTION
+    The function checks whether a substitution of the field
+    occurrence for an equal item is valid.
+
+  NOTES
+    The following statement is not always true:
+    x=y => F(x)=F(x/y).
+    This means substitution of an item for an equal item not always
+    yields an equavalent condition.
+    Here's an example:
+      'a'='a '
+      (LENGTH('a')=1) != (LENGTH('a ')=2)
+    Such a substitution is surely valid if either the substituted
+    field is not of a STRING type or if it is an argument of
+    a comparison  predicate.  
+
+  RETURN
+    TRUE   substitution is valid
+    FALSE  otherwise
+*/
+
+bool Item_field::subst_argument_checker(byte **arg)
+{
+  return (result_type() != STRING_RESULT) || (*arg);
+}
+
+
+/*
   Set a pointer to the multiple equality the field reference belongs to
   (if any)
    
   SYNOPSIS
     equal_fields_propagator()
-    arg - reference to list of multiple equalities where
-          the field (this object) is to be looked for
+      arg - reference to list of multiple equalities where
+            the field (this object) is to be looked for
   
   DESCRIPTION
     The function looks for a multiple equality containing the field item
@@ -3764,7 +3799,7 @@ Item_equal *Item_field::find_item_equal(COND_EQUAL *cond_equal)
 
   NOTES
     This function is supposed to be called as a callback parameter in calls
-    of the transform method.  
+    of the compile method.  
 
   RETURN VALUES
     pointer to the replacing constant item, if the field item was substituted 
diff --git a/sql/item.h b/sql/item.h
index e3df0fdf389..cdd0f863aea 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -410,7 +410,19 @@ public:
 };
 
 
-typedef bool (Item::*Item_processor)(byte *arg);
+typedef bool (Item::*Item_processor) (byte *arg);
+/*
+  Analyzer function
+    SYNOPSIS
+      argp   in/out IN:  Analysis parameter
+                    OUT: Parameter to be passed to the transformer
+
+    RETURN 
+      TRUE   Invoke the transformer
+      FALSE  Don't do it
+
+*/
+typedef bool (Item::*Item_analyzer) (byte **argp);
 typedef Item* (Item::*Item_transformer) (byte *arg);
 typedef void (*Cond_traverser) (const Item *item, void *arg);
 
@@ -739,6 +751,30 @@ public:
     return (this->*transformer)(arg);
   }
 
+  /*
+    This function performs a generic "compilation" of the Item tree.
+    The process of compilation is assumed to go as follows: 
+    
+    compile()
+    { 
+      if (this->*some_analyzer(...))
+      {
+        compile children if any;
+        this->*some_transformer(...);
+      }
+    }
+
+    i.e. analysis is performed top-down while transformation is done
+    bottom-up.      
+  */
+  virtual Item* compile(Item_analyzer analyzer, byte **arg_p,
+                        Item_transformer transformer, byte *arg_t)
+  {
+    if ((this->*analyzer) (arg_p))
+      return ((this->*transformer) (arg_t));
+    return 0;
+  }
+
    virtual void traverse_cond(Cond_traverser traverser,
                               void *arg, traverse_order order)
    {
@@ -753,6 +789,12 @@ public:
   virtual bool change_context_processor(byte *context) { return 0; }
   virtual bool reset_query_id_processor(byte *query_id) { return 0; }
   virtual bool is_expensive_processor(byte *arg) { return 0; }
+  virtual bool subst_argument_checker(byte **arg)
+  { 
+    if (*arg)
+      *arg= NULL; 
+    return TRUE;     
+  }
 
   virtual Item *equal_fields_propagator(byte * arg) { return this; }
   virtual Item *set_no_const_sub(byte *arg) { return this; }
@@ -1254,6 +1296,7 @@ public:
     return field->can_be_compared_as_longlong();
   }
   Item_equal *find_item_equal(COND_EQUAL *cond_equal);
+  bool subst_argument_checker(byte **arg);
   Item *equal_fields_propagator(byte *arg);
   Item *set_no_const_sub(byte *arg);
   Item *replace_equal_field(byte *arg);
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index dbf380232c4..3694c01d0aa 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -2747,16 +2747,16 @@ bool Item_cond::walk(Item_processor processor, byte *arg)
    
   SYNOPSIS
     transform()
-    transformer   the transformer callback function to be applied to the nodes
-                  of the tree of the object
-    arg           parameter to be passed to the transformer
+      transformer   the transformer callback function to be applied to the nodes
+                    of the tree of the object
+      arg           parameter to be passed to the transformer
   
   DESCRIPTION
-    The function recursively applies the transform method with the
-    same transformer to each member item of the condition list.
+    The function recursively applies the transform method to each
+     member item of the condition list.
     If the call of the method for a member item returns a new item
     the old item is substituted for a new one.
-    After this the transform method is applied to the root node
+    After this the transformer is applied to the root node
     of the Item_cond object. 
      
   RETURN VALUES
@@ -2778,6 +2778,55 @@ Item *Item_cond::transform(Item_transformer transformer, byte *arg)
   return Item_func::transform(transformer, arg);
 }
 
+
+/*
+  Compile Item_cond object with a processor and a transformer callback functions
+   
+  SYNOPSIS
+    compile()
+      analyzer      the analyzer callback function to be applied to the nodes
+                    of the tree of the object
+      arg_p         in/out parameter to be passed to the analyzer
+      transformer   the transformer callback function to be applied to the nodes
+                    of the tree of the object
+      arg_t         parameter to be passed to the transformer
+  
+  DESCRIPTION
+    First the function applies the analyzer to the root node of
+    the Item_func object. Then if the analyzer succeeeds (returns TRUE)
+    the function recursively applies the compile method to member
+    item of the condition list.
+    If the call of the method for a member item returns a new item
+    the old item is substituted for a new one.
+    After this the transformer is applied to the root node
+    of the Item_cond object. 
+     
+  RETURN VALUES
+    Item returned as the result of transformation of the root node 
+*/
+
+Item *Item_cond::compile(Item_analyzer analyzer, byte **arg_p,
+                         Item_transformer transformer, byte *arg_t)
+{
+  if (!(this->*analyzer)(arg_p))
+    return 0;
+  
+  List_iterator<Item> li(list);
+  Item *item;
+  while ((item= li++))
+  {
+    /* 
+      The same parameter value of arg_p must be passed
+      to analyze any argument of the condition formula.
+    */   
+    byte *arg_v= *arg_p;
+    Item *new_item= item->compile(analyzer, &arg_v, transformer, arg_t);
+    if (new_item && new_item != item)
+      li.replace(new_item);
+  }
+  return Item_func::transform(transformer, arg_t);
+}
+
 void Item_cond::traverse_cond(Cond_traverser traverser,
                               void *arg, traverse_order order)
 {
diff --git a/sql/item_cmpfunc.h b/sql/item_cmpfunc.h
index 47f9f2aa98f..f2c43833bd9 100644
--- a/sql/item_cmpfunc.h
+++ b/sql/item_cmpfunc.h
@@ -240,6 +240,7 @@ public:
   }
   Item *neg_transformer(THD *thd);
   virtual Item *negated_item();
+  bool subst_argument_checker(byte **arg) { return TRUE; }
 };
 
 class Item_func_not :public Item_bool_func
@@ -1171,6 +1172,9 @@ public:
   Item *transform(Item_transformer transformer, byte *arg);
   void traverse_cond(Cond_traverser, void *arg, traverse_order order);
   void neg_arguments(THD *thd);
+  bool subst_argument_checker(byte **arg) { return TRUE; }
+  Item *compile(Item_analyzer analyzer, byte **arg_p,
+                Item_transformer transformer, byte *arg_t);
 };
 
 
diff --git a/sql/item_func.cc b/sql/item_func.cc
index e699669dcc5..c5588e43b49 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -234,22 +234,21 @@ void Item_func::traverse_cond(Cond_traverser traverser,
 }
 
 
-
 /*
   Transform an Item_func object with a transformer callback function
    
   SYNOPSIS
     transform()
-    transformer   the transformer callback function to be applied to the nodes
-                  of the tree of the object
-    argument      parameter to be passed to the transformer
+      transformer   the transformer callback function to be applied to the nodes
+                    of the tree of the object
+      argument      parameter to be passed to the transformer
   
   DESCRIPTION
-    The function recursively applies the transform method with the
-    same transformer to each argument the function.
-    If the call of the method for a member item returns a new item
+    The function recursively applies the transform method to each
+    argument of the Item_func node.
+    If the call of the method for an argument item returns a new item
     the old item is substituted for a new one.
-    After this the transform method is applied to the root node
+    After this the transformer is applied to the root node
     of the Item_func object. 
      
   RETURN VALUES
@@ -274,6 +273,55 @@ Item *Item_func::transform(Item_transformer transformer, byte *argument)
 }
 
 
+/*
+  Compile Item_func object with a processor and a transformer callback functions
+   
+  SYNOPSIS
+    compile()
+      analyzer      the analyzer callback function to be applied to the nodes
+                    of the tree of the object
+      arg_p         in/out parameter to be passed to the processor
+      transformer   the transformer callback function to be applied to the nodes
+                    of the tree of the object
+      arg_t         parameter to be passed to the transformer
+  
+  DESCRIPTION
+    First the function applies the analyzer to the root node of
+    the Item_func object. Then if the analizer succeeeds (returns TRUE)
+    the function recursively applies the compile method to each argument
+    of the Item_func node.
+    If the call of the method for an argument item returns a new item
+    the old item is substituted for a new one.
+    After this the transformer is applied to the root node
+    of the Item_func object. 
+     
+  RETURN VALUES
+    Item returned as the result of transformation of the root node 
+*/
+
+Item *Item_func::compile(Item_analyzer analyzer, byte **arg_p,
+                         Item_transformer transformer, byte *arg_t)
+{
+  if (!(this->*analyzer)(arg_p))
+    return 0;
+  if (arg_count)
+  {
+    Item **arg,**arg_end;
+    for (arg= args, arg_end= args+arg_count; arg != arg_end; arg++)
+    {
+      /* 
+        The same parameter value of arg_p must be passed
+        to analyze any argument of the condition formula.
+      */   
+      byte *arg_v= *arg_p;
+      Item *new_item= (*arg)->compile(analyzer, &arg_v, transformer, arg_t);
+      if (new_item && *arg != new_item)
+        current_thd->change_item_tree(arg, new_item);
+    }
+  }
+  return (this->*transformer)(arg_t);
+}
+
 /* See comments in Item_cmp_func::split_sum_func() */
 
 void Item_func::split_sum_func(THD *thd, Item **ref_pointer_array,
diff --git a/sql/item_func.h b/sql/item_func.h
index c15b0b854b0..0d09bac4e86 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -187,6 +187,8 @@ public:
   }
   bool walk(Item_processor processor, byte *arg);
   Item *transform(Item_transformer transformer, byte *arg);
+  Item* compile(Item_analyzer analyzer, byte **arg_p,
+                Item_transformer transformer, byte *arg_t);
   void traverse_cond(Cond_traverser traverser,
                      void * arg, traverse_order order);
   bool is_expensive_processor(byte *arg);
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index 0d2a5b3b080..bcd8270e52f 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -290,7 +290,9 @@ Item_sum::Item_sum(THD *thd, Item_sum *item):
 
 void Item_sum::mark_as_sum_func()
 {
-  current_thd->lex->current_select->with_sum_func= 1;
+  SELECT_LEX *cur_select= current_thd->lex->current_select;
+  cur_select->n_sum_items++;
+  cur_select->with_sum_func= 1;
   with_sum_func= 1;
 }
 
diff --git a/sql/mysql_priv.h b/sql/mysql_priv.h
index 3178569abc6..620992b8cc7 100644
--- a/sql/mysql_priv.h
+++ b/sql/mysql_priv.h
@@ -425,6 +425,7 @@ void view_store_options(THD *thd, st_table_list *table, String *buff);
 #define TL_OPTION_UPDATING	1
 #define TL_OPTION_FORCE_INDEX	2
 #define TL_OPTION_IGNORE_LEAVES 4
+#define TL_OPTION_ALIAS         8
 
 /* Some portable defines */
 
diff --git a/sql/opt_range.cc b/sql/opt_range.cc
index 71ba63dcf98..6189d0412b3 100644
--- a/sql/opt_range.cc
+++ b/sql/opt_range.cc
@@ -4129,6 +4129,7 @@ get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
   MEM_ROOT *alloc= param->mem_root;
   char *str;
   ulong orig_sql_mode;
+  int err;
   DBUG_ENTER("get_mm_leaf");
 
   /*
@@ -4280,7 +4281,13 @@ get_mm_leaf(PARAM *param, COND *conf_func, Field *field, KEY_PART *key_part,
       (field->type() == FIELD_TYPE_DATE ||
        field->type() == FIELD_TYPE_DATETIME))
     field->table->in_use->variables.sql_mode|= MODE_INVALID_DATES;
-  if (value->save_in_field_no_warnings(field, 1) < 0)
+  err= value->save_in_field_no_warnings(field, 1);
+  if (err > 0 && field->cmp_type() != value->result_type())
+  {
+    tree= 0;
+    goto end;
+  } 
+  if (err < 0)
   {
     field->table->in_use->variables.sql_mode= orig_sql_mode;
     /* This happens when we try to insert a NULL field in a not null column */
diff --git a/sql/opt_sum.cc b/sql/opt_sum.cc
index 1f6190241a3..d17c42bca38 100644
--- a/sql/opt_sum.cc
+++ b/sql/opt_sum.cc
@@ -191,7 +191,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
             Type of range for the key part for this field will be
             returned in range_fl.
           */
-          if ((outer_tables & table->map) ||
+          if (table->file->inited || (outer_tables & table->map) ||
               !find_key_for_maxmin(0, &ref, item_field->field, conds,
                                    &range_fl, &prefix_len))
           {
@@ -278,7 +278,7 @@ int opt_sum_query(TABLE_LIST *tables, List<Item> &all_fields,COND *conds)
             Type of range for the key part for this field will be
             returned in range_fl.
           */
-          if ((outer_tables & table->map) ||
+          if (table->file->inited || (outer_tables & table->map) ||
 	          !find_key_for_maxmin(1, &ref, item_field->field, conds,
 				                   &range_fl, &prefix_len))
           {
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 563ebce4ff7..035c575724e 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -1521,10 +1521,10 @@ bool st_select_lex::setup_ref_array(THD *thd, uint order_group_num)
   */
   Query_arena *arena= thd->stmt_arena;
   return (ref_pointer_array=
-          (Item **)arena->alloc(sizeof(Item*) *
-                                (item_list.elements +
-                                 select_n_having_items +
-                                 order_group_num)* 5)) == 0;
+          (Item **)arena->alloc(sizeof(Item*) * (n_child_sum_items +
+                                                 item_list.elements +
+                                                 select_n_having_items +
+                                                 order_group_num)*5)) == 0;
 }
 
 
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 220d928ccf7..fe6d60a218d 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -548,6 +548,12 @@ public:
   bool  braces;   	/* SELECT ... UNION (SELECT ... ) <- this braces */
   /* TRUE when having fix field called in processing of this SELECT */
   bool having_fix_field;
+
+  /* Number of Item_sum-derived objects in this SELECT */
+  uint n_sum_items;
+  /* Number of Item_sum-derived objects in children and descendant SELECTs */
+  uint n_child_sum_items;
+
   /* explicit LIMIT clause was used */
   bool explicit_limit;
   /*
@@ -640,7 +646,7 @@ public:
   bool test_limit();
 
   friend void lex_start(THD *thd, uchar *buf, uint length);
-  st_select_lex() {}
+  st_select_lex() : n_sum_items(0), n_child_sum_items(0) {}
   void make_empty_select()
   {
     init_query();
diff --git a/sql/sql_list.h b/sql/sql_list.h
index b2bcc4ea401..afad6d0f6ac 100644
--- a/sql/sql_list.h
+++ b/sql/sql_list.h
@@ -94,9 +94,9 @@ public:
   inline base_list() { empty(); }
   inline base_list(const base_list &tmp) :Sql_alloc()
   {
-    elements=tmp.elements;
-    first=tmp.first;
-    last=tmp.last;
+    elements= tmp.elements;
+    first= tmp.first;
+    last= elements ? tmp.last : &first;
   }
   inline base_list(bool error) { }
   inline bool push_back(void *info)
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index 905e8cdc71a..8761b4317b5 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -6083,6 +6083,7 @@ bool add_to_list(THD *thd, SQL_LIST &list,Item *item,bool asc)
     table_options	A set of the following bits:
 			TL_OPTION_UPDATING	Table will be updated
 			TL_OPTION_FORCE_INDEX	Force usage of index
+			TL_OPTION_ALIAS	        an alias in multi table DELETE
     lock_type		How table should be locked
     use_index		List of indexed used in USE INDEX
     ignore_index	List of indexed used in IGNORE INDEX
@@ -6111,7 +6112,8 @@ TABLE_LIST *st_select_lex::add_table_to_list(THD *thd,
   if (!table)
     DBUG_RETURN(0);				// End of memory
   alias_str= alias ? alias->str : table->table.str;
-  if (check_table_name(table->table.str, table->table.length))
+  if (!test(table_options & TL_OPTION_ALIAS) && 
+      check_table_name(table->table.str, table->table.length))
   {
     my_error(ER_WRONG_TABLE_NAME, MYF(0), table->table.str);
     DBUG_RETURN(0);
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 0ef4cb6da9d..e706cf1e965 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -1324,7 +1324,7 @@ JOIN::exec()
   }
   (void) result->prepare2(); // Currently, this cannot fail.
 
-  if (!tables_list)
+  if (!tables_list && (tables || !select_lex->with_sum_func))
   {                                           // Only test of functions
     if (select_options & SELECT_DESCRIBE)
       select_describe(this, FALSE, FALSE, FALSE,
@@ -1364,7 +1364,12 @@ JOIN::exec()
     thd->examined_row_count= 0;
     DBUG_VOID_RETURN;
   }
-  thd->limit_found_rows= thd->examined_row_count= 0;
+  /* 
+    don't reset the found rows count if there're no tables
+    as FOUND_ROWS() may be called.
+  */  
+  if (tables)
+    thd->limit_found_rows= thd->examined_row_count= 0;
 
   if (zero_result_cause)
   {
@@ -1403,7 +1408,8 @@ JOIN::exec()
     having= tmp_having;
     select_describe(this, need_tmp,
 		    order != 0 && !skip_sort_order,
-		    select_distinct);
+		    select_distinct,
+                    !tables ? "No tables used" : NullS);
     DBUG_VOID_RETURN;
   }
 
@@ -6351,29 +6357,30 @@ finish:
 
   
 /* 
-  Check whether an item is a simple equality predicate and if so
-  create/find a multiple equality for this predicate
+  Check whether an equality can be used to build multiple equalities
 
   SYNOPSIS
-    check_equality()
-    item       item to check
-    cond_equal multiple equalities that must hold together with the predicate
+    check_simple_equality()
+      left_item   left term of the quality to be checked
+      right_item  right term of the equality to be checked
+      item        equality item if the equality originates from a condition
+                  predicate, 0 if the equality is the result of row elimination
+      cond_equal  multiple equalities that must hold together with the equality
 
   DESCRIPTION
-    This function first checks whether an item is a simple equality i.e.
-    the one that equates a field with another field or a constant
-    (item=constant_item or item=field_item).
-    If this is the case the function looks a for a multiple equality
+    This function first checks whether the equality (left_item=right_item)
+    is a simple equality i.e. the one that equates a field with another field
+    or a constant (field=field_item or field=const_item).
+    If this is the case the function looks for a multiple equality
     in the lists referenced directly or indirectly by cond_equal inferring
     the given simple equality. If it doesn't find any, it builds a multiple
     equality that covers the predicate, i.e. the predicate can be inferred
-    from it.
+    from this multiple equality.
     The built multiple equality could be obtained in such a way:
     create a binary  multiple equality equivalent to the predicate, then
     merge it, if possible, with one of old multiple equalities.
     This guarantees that the set of multiple equalities covering equality
-    predicates will
-    be minimal.
+    predicates will be minimal.
 
   EXAMPLE
     For the where condition
@@ -6391,7 +6398,7 @@ finish:
     and will transform *cond_equal into (ptr(CE),[Item_equal(f,e)]).
 
   NOTES
-    Now only fields that have the same type defintions (verified by
+    Now only fields that have the same type definitions (verified by
     the Field::eq_def method) are placed to the same multiple equalities.
     Because of this some equality predicates are not eliminated and
     can be used in the constant propagation procedure.
@@ -6424,177 +6431,289 @@ finish:
     copying would be much more complicated.
 
   RETURN
-    TRUE  - if the predicate is a simple equality predicate
-    FALSE - otherwise
+    TRUE    if the predicate is a simple equality predicate to be used
+            for building multiple equalities
+    FALSE   otherwise
 */
 
-static bool check_equality(Item *item, COND_EQUAL *cond_equal)
+static bool check_simple_equality(Item *left_item, Item *right_item,
+                                  Item *item, COND_EQUAL *cond_equal)
 {
-  if (item->type() == Item::FUNC_ITEM &&
-         ((Item_func*) item)->functype() == Item_func::EQ_FUNC)
+  if (left_item->type() == Item::REF_ITEM &&
+      ((Item_ref*)left_item)->ref_type() == Item_ref::VIEW_REF)
   {
-    Item *left_item= ((Item_func*) item)->arguments()[0];
-    Item *right_item= ((Item_func*) item)->arguments()[1];
+    if (((Item_ref*)left_item)->depended_from)
+      return FALSE;
+    left_item= left_item->real_item();
+  }
+  if (right_item->type() == Item::REF_ITEM &&
+      ((Item_ref*)right_item)->ref_type() == Item_ref::VIEW_REF)
+  {
+    if (((Item_ref*)right_item)->depended_from)
+      return FALSE;
+    right_item= right_item->real_item();
+  }
+  if (left_item->type() == Item::FIELD_ITEM &&
+      right_item->type() == Item::FIELD_ITEM &&
+      !((Item_field*)left_item)->depended_from &&
+      !((Item_field*)right_item)->depended_from)
+  {
+    /* The predicate the form field1=field2 is processed */
+
+    Field *left_field= ((Item_field*) left_item)->field;
+    Field *right_field= ((Item_field*) right_item)->field;
+
+    if (!left_field->eq_def(right_field))
+      return FALSE;
+
+    /* Search for multiple equalities containing field1 and/or field2 */
+    bool left_copyfl, right_copyfl;
+    Item_equal *left_item_equal=
+               find_item_equal(cond_equal, left_field, &left_copyfl);
+    Item_equal *right_item_equal= 
+               find_item_equal(cond_equal, right_field, &right_copyfl);
+
+    /* As (NULL=NULL) != TRUE we can't just remove the predicate f=f */
+    if (left_field->eq(right_field)) /* f = f */
+      return (!(left_field->maybe_null() && !left_item_equal)); 
 
-    if (left_item->type() == Item::REF_ITEM &&
-        ((Item_ref*)left_item)->ref_type() == Item_ref::VIEW_REF)
+    if (left_item_equal && left_item_equal == right_item_equal)
     {
-      if (((Item_ref*)left_item)->depended_from)
-        return FALSE;
-      left_item= left_item->real_item();
+      /* 
+        The equality predicate is inference of one of the existing
+        multiple equalities, i.e the condition is already covered
+        by upper level equalities
+      */
+       return TRUE;
     }
-    if (right_item->type() == Item::REF_ITEM &&
-        ((Item_ref*)right_item)->ref_type() == Item_ref::VIEW_REF)
+      
+    /* Copy the found multiple equalities at the current level if needed */
+    if (left_copyfl)
     {
-      if (((Item_ref*)right_item)->depended_from)
-        return FALSE;
-      right_item= right_item->real_item();
+      /* left_item_equal of an upper level contains left_item */
+      left_item_equal= new Item_equal(left_item_equal);
+      cond_equal->current_level.push_back(left_item_equal);
     }
-    if (left_item->type() == Item::FIELD_ITEM &&
-        right_item->type() == Item::FIELD_ITEM &&
-        !((Item_field*)left_item)->depended_from &&
-        !((Item_field*)right_item)->depended_from)
+    if (right_copyfl)
     {
-      /* The predicate the form field1=field2 is processed */
+      /* right_item_equal of an upper level contains right_item */
+      right_item_equal= new Item_equal(right_item_equal);
+      cond_equal->current_level.push_back(right_item_equal);
+    }
 
-      Field *left_field= ((Item_field*) left_item)->field;
-      Field *right_field= ((Item_field*) right_item)->field;
+    if (left_item_equal)
+    { 
+      /* left item was found in the current or one of the upper levels */
+      if (! right_item_equal)
+        left_item_equal->add((Item_field *) right_item);
+      else
+      {
+        /* Merge two multiple equalities forming a new one */
+        left_item_equal->merge(right_item_equal);
+        /* Remove the merged multiple equality from the list */
+        List_iterator<Item_equal> li(cond_equal->current_level);
+        while ((li++) != right_item_equal);
+        li.remove();
+      }
+    }
+    else
+    { 
+      /* left item was not found neither the current nor in upper levels  */
+      if (right_item_equal)
+        right_item_equal->add((Item_field *) left_item);
+      else 
+      {
+        /* None of the fields was found in multiple equalities */
+        Item_equal *item= new Item_equal((Item_field *) left_item,
+                                         (Item_field *) right_item);
+        cond_equal->current_level.push_back(item);
+      }
+    }
+    return TRUE;
+  }
 
-      if (!left_field->eq_def(right_field))
-        return FALSE;
+  {
+    /* The predicate of the form field=const/const=field is processed */
+    Item *const_item= 0;
+    Item_field *field_item= 0;
+    if (left_item->type() == Item::FIELD_ITEM &&
+        !((Item_field*)left_item)->depended_from &&
+        right_item->const_item())
+    {
+      field_item= (Item_field*) left_item;
+      const_item= right_item;
+    }
+    else if (right_item->type() == Item::FIELD_ITEM &&
+             !((Item_field*)right_item)->depended_from &&
+             left_item->const_item())
+    {
+      field_item= (Item_field*) right_item;
+      const_item= left_item;
+    }
 
-      if (left_field->eq(right_field))  /* f = f */
-        return TRUE;
-      
-      /* Search for multiple equalities containing field1 and/or field2 */
-      bool left_copyfl, right_copyfl;
-      Item_equal *left_item_equal=
-                 find_item_equal(cond_equal, left_field, &left_copyfl);
-      Item_equal *right_item_equal= 
-                 find_item_equal(cond_equal, right_field, &right_copyfl);
+    if (const_item &&
+        field_item->result_type() == const_item->result_type())
+    {
+      bool copyfl;
 
-      if (left_item_equal && left_item_equal == right_item_equal)
+      if (field_item->result_type() == STRING_RESULT)
       {
-        /* 
-           The equality predicate is inference of one of the existing
-           multiple equalities, i.e the condition is already covered
-           by upper level equalities
-        */
-          return TRUE;
+        CHARSET_INFO *cs= ((Field_str*) field_item->field)->charset();
+        if (!item)
+        {
+          Item_func_eq *eq_item;
+          if ((eq_item= new Item_func_eq(left_item, right_item)))
+            return FALSE;
+          eq_item->set_cmp_func();
+          eq_item->quick_fix_field();
+          item= eq_item;
+        }  
+        if ((cs != ((Item_func *) item)->compare_collation()) ||
+            !cs->coll->propagate(cs, 0, 0))
+          return FALSE;
       }
-      
-      /* Copy the found multiple equalities at the current level if needed */
-      if (left_copyfl)
+
+      Item_equal *item_equal = find_item_equal(cond_equal,
+                                               field_item->field, &copyfl);
+      if (copyfl)
       {
-        /* left_item_equal of an upper level contains left_item */
-        left_item_equal= new Item_equal(left_item_equal);
-        cond_equal->current_level.push_back(left_item_equal);
+        item_equal= new Item_equal(item_equal);
+        cond_equal->current_level.push_back(item_equal);
       }
-      if (right_copyfl)
+      if (item_equal)
       {
-        /* right_item_equal of an upper level contains right_item */
-        right_item_equal= new Item_equal(right_item_equal);
-        cond_equal->current_level.push_back(right_item_equal);
-      }
-
-      if (left_item_equal)
-      { 
-        /* left item was found in the current or one of the upper levels */
-        if (! right_item_equal)
-          left_item_equal->add((Item_field *) right_item);
-        else
-        {
-          /* Merge two multiple equalities forming a new one */
-          left_item_equal->merge(right_item_equal);
-          /* Remove the merged multiple equality from the list */
-          List_iterator<Item_equal> li(cond_equal->current_level);
-          while ((li++) != right_item_equal);
-          li.remove();
-        }
+        /* 
+          The flag cond_false will be set to 1 after this, if item_equal
+          already contains a constant and its value is  not equal to
+          the value of const_item.
+        */
+        item_equal->add(const_item);
       }
       else
-      { 
-        /* left item was not found neither the current nor in upper levels  */
-         if (right_item_equal)
-           right_item_equal->add((Item_field *) left_item);
-         else 
-         {
-           /* None of the fields was found in multiple equalities */
-           Item_equal *item= new Item_equal((Item_field *) left_item,
-                                            (Item_field *) right_item);
-           cond_equal->current_level.push_back(item);
-         }
+      {
+        item_equal= new Item_equal(const_item, field_item);
+        cond_equal->current_level.push_back(item_equal);
       }
       return TRUE;
     }
+  }
+  return FALSE;
+}
 
-    {
-      /* The predicate of the form field=const/const=field is processed */
-      Item *const_item= 0;
-      Item_field *field_item= 0;
-      if (left_item->type() == Item::FIELD_ITEM &&
-          !((Item_field*)left_item)->depended_from &&
-          right_item->const_item())
-      {
-        field_item= (Item_field*) left_item;
-        const_item= right_item;
-      }
-      else if (right_item->type() == Item::FIELD_ITEM &&
-               !((Item_field*)right_item)->depended_from &&
-               left_item->const_item())
-      {
-        field_item= (Item_field*) right_item;
-        const_item= left_item;
-      }
 
-      if (const_item &&
-          field_item->result_type() == const_item->result_type())
-      {
-        bool copyfl;
+/* 
+  Convert row equalities into a conjunction of regular equalities
 
-        if (field_item->result_type() == STRING_RESULT)
-        {
-          CHARSET_INFO *cs= ((Field_str*) field_item->field)->charset();
-          if ((cs != ((Item_cond *) item)->compare_collation()) ||
-              !cs->coll->propagate(cs, 0, 0))
-            return FALSE;
-        }
+  SYNOPSIS
+    check_row_equality()
+      left_row   left term of the row equality to be processed     
+      right_row  right term of the row equality to be processed
+      cond_equal multiple equalities that must hold together with the predicate
+      eq_list    results of conversions of row equalities that are not simple
+                 enough to form multiple equalities
 
-        Item_equal *item_equal = find_item_equal(cond_equal,
-                                                 field_item->field, &copyfl);
-        if (copyfl)
-        {
-          item_equal= new Item_equal(item_equal);
-          cond_equal->current_level.push_back(item_equal);
-        }
-        if (item_equal)
-        {
-          /* 
-            The flag cond_false will be set to 1 after this, if item_equal
-            already contains a constant and its value is  not equal to
-            the value of const_item.
-          */
-          item_equal->add(const_item);
-        }
-        else
-        {
-          item_equal= new Item_equal(const_item, field_item);
-          cond_equal->current_level.push_back(item_equal);
-        }
-        return TRUE;
-      }
+  DESCRIPTION
+    The function converts a row equality of the form (E1,...,En)=(E'1,...,E'n)
+    into a list of equalities E1=E'1,...,En=E'n. For each of these equalities
+    Ei=E'i the function checks whether it is a simple equality or a row equality.
+    If it is a simple equality it is used to expand multiple equalities of
+    cond_equal. If it is a row equality it converted to a sequence of equalities
+    between row elements. If Ei=E'i is neither a simple equality nor a row
+    equality the item for this predicate is added to eq_list.
+
+  RETURN
+    TRUE    if conversion has succeeded (no fatal error) 
+    FALSE   otherwise  
+*/
+ 
+static bool check_row_equality(Item *left_row, Item_row *right_row,
+                               COND_EQUAL *cond_equal, List<Item>* eq_list)
+{ 
+  uint n= left_row->cols();
+  for (uint i= 0 ; i < n; i++)
+  {
+    bool is_converted;
+    Item *left_item= left_row->el(i);
+    Item *right_item= right_row->el(i);
+    if (left_item->type() == Item::ROW_ITEM &&
+        right_item->type() == Item::ROW_ITEM)
+      is_converted= check_row_equality((Item_row *) left_item,
+	                               (Item_row *) right_item,
+				       cond_equal, eq_list);
+    else 
+      is_converted= check_simple_equality(left_item, right_item, 0, cond_equal);
+
+    if (!is_converted)  
+    {
+      Item_func_eq *eq_item;
+      if (!(eq_item= new Item_func_eq(left_item, right_item)))
+        return FALSE;
+      eq_item->set_cmp_func();
+      eq_item->quick_fix_field();
+      eq_list->push_back(eq_item);
     }
   }
+  return TRUE;
+}
+
+
+/* 
+  Eliminate row equalities and form multiple equalities predicates 
+
+  SYNOPSIS
+    check_equality()
+      item       predicate to process     
+      cond_equal multiple equalities that must hold together with the predicate
+      eq_list    results of conversions of row equalities that are not simple
+                 enough to form multiple equalities
+
+  DESCRIPTION
+    This function checks whether the item is a simple equality
+    i.e. the one that equates a field with another field or a constant
+    (field=field_item or field=constant_item), or, a row equality.
+    For a simple equality the function looks for a multiple equality
+    in the lists referenced directly or indirectly by cond_equal inferring
+    the given simple equality. If it doesn't find any, it builds/expands
+    multiple equality that covers the predicate.
+    Row equalities are eliminated substituted for conjunctive regular equalities
+    which are treated in the same way as original equality predicates.
+
+  RETURN
+    TRUE   if re-writing rules have been applied
+    FALSE  otherwise, i.e.
+           if the predicate is not an equality,
+           or, if the equality is neither a simple one nor a row equality,
+           or, if the procedure fails by a fatal error.
+*/
+
+static bool check_equality(Item *item, COND_EQUAL *cond_equal,
+                           List<Item> *eq_list)
+{
+  if (item->type() == Item::FUNC_ITEM &&
+         ((Item_func*) item)->functype() == Item_func::EQ_FUNC)
+  {
+    Item *left_item= ((Item_func*) item)->arguments()[0];
+    Item *right_item= ((Item_func*) item)->arguments()[1];
+
+    if (left_item->type() == Item::ROW_ITEM &&
+        right_item->type() == Item::ROW_ITEM)
+      return check_row_equality((Item_row *) left_item,
+                                (Item_row *) right_item,
+                                cond_equal, eq_list);
+    else 
+      return check_simple_equality(left_item, right_item, item, cond_equal);
+  } 
   return FALSE;
 }
 
+                          
 /* 
   Replace all equality predicates in a condition by multiple equality items
 
   SYNOPSIS
     build_equal_items_for_cond()
-    cond       condition(expression) where to make replacement
-    inherited  path to all inherited multiple equality items
+      cond       condition(expression) where to make replacement
+      inherited  path to all inherited multiple equality items
 
   DESCRIPTION
     At each 'and' level the function detects items for equality predicates
@@ -6608,7 +6727,9 @@ static bool check_equality(Item *item, COND_EQUAL *cond_equal)
     The function also traverses the cond tree and and for each field reference
     sets a pointer to the multiple equality item containing the field, if there
     is any. If this multiple equality equates fields to a constant the
-    function replace the field reference by the constant.
+    function replaces the field reference by the constant in the cases 
+    when the field is not of a string type or when the field reference is
+    just an argument of a comparison predicate.
     The function also determines the maximum number of members in 
     equality lists of each Item_cond_and object assigning it to
     cond_equal->max_members of this object and updating accordingly
@@ -6659,10 +6780,12 @@ static COND *build_equal_items_for_cond(COND *cond,
   Item_equal *item_equal;
   uint members;
   COND_EQUAL cond_equal;
+  COND *new_cond;
   cond_equal.upper_levels= inherited;
 
   if (cond->type() == Item::COND_ITEM)
   {
+    List<Item> eq_list;
     bool and_level= ((Item_cond*) cond)->functype() ==
       Item_func::COND_AND_FUNC;
     List<Item> *args= ((Item_cond*) cond)->argument_list();
@@ -6685,7 +6808,7 @@ static COND *build_equal_items_for_cond(COND *cond,
           structure here because it's restored before each
           re-execution of any prepared statement/stored procedure.
         */
-        if (check_equality(item, &cond_equal))
+        if (check_equality(item, &cond_equal, &eq_list))
           li.remove();
       }
 
@@ -6732,10 +6855,14 @@ static COND *build_equal_items_for_cond(COND *cond,
       }
     }
     if (and_level)
+    {
+      args->concat(&eq_list);
       args->concat((List<Item> *)&cond_equal.current_level);
+    }
   }
   else if (cond->type() == Item::FUNC_ITEM)
   {
+    List<Item> eq_list;
     /*
       If an equality predicate forms the whole and level,
       we call it standalone equality and it's processed here.
@@ -6746,19 +6873,57 @@ static COND *build_equal_items_for_cond(COND *cond,
       for WHERE a=b AND c=d AND (b=c OR d=5)
       b=c is replaced by =(a,b,c,d).  
      */
-    if (check_equality(cond, &cond_equal) &&
-        (item_equal= cond_equal.current_level.pop()))
+    if (check_equality(cond, &cond_equal, &eq_list))
     {
-      item_equal->fix_length_and_dec();
-      item_equal->update_used_tables();
-      return item_equal;
+      int n= cond_equal.current_level.elements + eq_list.elements;
+      if (n == 0)
+        return new Item_int((longlong) 1,1);
+      else if (n == 1)
+      {
+        if ((item_equal= cond_equal.current_level.pop()))
+        {
+          item_equal->fix_length_and_dec();
+          item_equal->update_used_tables();
+          return item_equal;
+	}
+        else
+          return eq_list.pop();
+      }
+      else
+      {
+        /* 
+          Here a new AND level must be created. It can happen only
+          when a row equality is processed as a standalone predicate.
+	*/
+        Item_cond_and *and_cond= new Item_cond_and(eq_list);
+        and_cond->quick_fix_field();
+        List<Item> *args= and_cond->argument_list();
+        List_iterator_fast<Item_equal> it(cond_equal.current_level);
+        while ((item_equal= it++))
+        {
+          item_equal->fix_length_and_dec();
+          item_equal->update_used_tables();
+          members= item_equal->members();
+          if (cond_equal.max_members < members)
+            cond_equal.max_members= members; 
+        }
+        and_cond->cond_equal= cond_equal;
+        args->concat((List<Item> *)&cond_equal.current_level);
+        
+        return and_cond;
+      }
     }
     /* 
       For each field reference in cond, not from equal item predicates,
       set a pointer to the multiple equality it belongs to (if there is any)
+      as soon the field is not of a string type or the field reference is
+      an argument of a comparison predicate. 
     */ 
-    cond= cond->transform(&Item::equal_fields_propagator,
-                            (byte *) inherited);
+    byte *is_subst_valid= (byte *) 1;
+    cond= cond->compile(&Item::subst_argument_checker,
+                        &is_subst_valid, 
+                        &Item::equal_fields_propagator,
+                        (byte *) inherited);
     cond->update_used_tables();
   }
   return cond;
@@ -7038,7 +7203,7 @@ static Item *eliminate_item_equal(COND *cond, COND_EQUAL *upper_levels,
 
 /* 
   Substitute every field reference in a condition by the best equal field 
-  and eliminate all multiplle equality predicates
+  and eliminate all multiple equality predicates
  
   SYNOPSIS
     substitute_for_best_equal_field()
@@ -9576,9 +9741,13 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
       table->file->ha_index_init(0);
   }
   /* Set up select_end */
-  join->join_tab[join->tables-1].next_select= setup_end_select_func(join);
+  Next_select_func end_select= setup_end_select_func(join);
+  if (join->tables)
+  {
+    join->join_tab[join->tables-1].next_select= end_select;
 
-  join_tab=join->join_tab+join->const_tables;
+    join_tab=join->join_tab+join->const_tables;
+  }
   join->send_records=0;
   if (join->tables == join->const_tables)
   {
@@ -9588,7 +9757,6 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
     */
     if (!join->conds || join->conds->val_int())
     {
-      Next_select_func end_select= join->join_tab[join->tables-1].next_select;
       error= (*end_select)(join,join_tab,0);
       if (error == NESTED_LOOP_OK || error == NESTED_LOOP_QUERY_LIMIT)
 	error= (*end_select)(join,join_tab,1);
@@ -9602,6 +9770,8 @@ do_select(JOIN *join,List<Item> *fields,TABLE *table,Procedure *procedure)
   }
   else
   {
+    DBUG_ASSERT(join->tables);
+    DBUG_ASSERT(join_tab);
     error= sub_select(join,join_tab,0);
     if (error == NESTED_LOOP_OK || error == NESTED_LOOP_NO_MORE_ROWS)
       error= sub_select(join,join_tab,1);
@@ -14221,9 +14391,12 @@ static void select_describe(JOIN *join, bool need_tmp_table, bool need_order,
 	item_list.push_back(new Item_string(table_name_buffer, len, cs));
       }
       else
-	item_list.push_back(new Item_string(table->alias,
-					    strlen(table->alias),
+      {
+        TABLE_LIST *tab=table->pos_in_table_list; 
+	item_list.push_back(new Item_string(tab->alias,
+					    strlen(tab->alias),
 					    cs));
+      }
       /* type */
       item_list.push_back(new Item_string(join_type_str[tab->type],
 					  strlen(join_type_str[tab->type]),
@@ -14410,8 +14583,8 @@ bool mysql_explain_union(THD *thd, SELECT_LEX_UNIT *unit, select_result *result)
     // drop UNCACHEABLE_EXPLAIN, because it is for internal usage only
     uint8 uncacheable= (sl->uncacheable & ~UNCACHEABLE_EXPLAIN);
     sl->type= (((&thd->lex->select_lex)==sl)?
-	       ((thd->lex->all_selects_list != sl) ? 
-		primary_key_name : "SIMPLE"):
+	       (sl->first_inner_unit() || sl->next_select() ? 
+		"PRIMARY" : "SIMPLE"):
 	       ((sl == first)?
 		((sl->linkage == DERIVED_TABLE_TYPE) ?
 		 "DERIVED":
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index d2aca27c836..97f6cdd27e4 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -725,8 +725,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 	predicate bit_expr bit_term bit_factor value_expr term factor
 	table_wild simple_expr udf_expr
 	expr_or_default set_expr_or_default interval_expr
-	param_marker singlerow_subselect singlerow_subselect_init
-	exists_subselect exists_subselect_init geometry_function
+	param_marker geometry_function
 	signed_literal now_or_signed_literal opt_escape
 	sp_opt_default
 	simple_ident_nospvar simple_ident_q
@@ -791,7 +790,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
 
 %type <variable> internal_variable_name
 
-%type <select_lex> in_subselect in_subselect_init
+%type <select_lex> subselect subselect_init
 	get_select_lex
 
 %type <boolfunc2creator> comp_op
@@ -3914,12 +3913,14 @@ select_paren:
 	      yyerror(ER(ER_SYNTAX_ERROR));
 	      YYABORT;
 	    }
-	  if (sel->linkage == UNION_TYPE &&
-	      !sel->master_unit()->first_select()->braces)
-	  {
-	    yyerror(ER(ER_SYNTAX_ERROR));
-	    YYABORT;
-	  }
+            if (sel->linkage == UNION_TYPE &&
+                !sel->master_unit()->first_select()->braces &&
+                sel->master_unit()->first_select()->linkage ==
+                UNION_TYPE)
+            {
+              yyerror(ER(ER_SYNTAX_ERROR));
+              YYABORT;
+            }
             /* select in braces, can't contain global parameters */
 	    if (sel->master_unit()->fake_select_lex)
               sel->master_unit()->global_parameters=
@@ -4177,37 +4178,37 @@ bool_pri:
 	| bool_pri EQUAL_SYM predicate	{ $$= new Item_func_equal($1,$3); }
 	| bool_pri comp_op predicate %prec EQ
 	  { $$= (*$2)(0)->create($1,$3); }
-	| bool_pri comp_op all_or_any in_subselect %prec EQ
-	  { $$= all_any_subquery_creator($1, $2, $3, $4); }
+	| bool_pri comp_op all_or_any '(' subselect ')' %prec EQ
+	  { $$= all_any_subquery_creator($1, $2, $3, $5); }
 	| predicate ;
 
 predicate:
-	 bit_expr IN_SYM '(' expr_list ')'
+        bit_expr IN_SYM '(' subselect ')'
+	  { $$= new Item_in_subselect($1, $4); }
+	| bit_expr not IN_SYM '(' subselect ')'
+          { $$= negate_expression(YYTHD, new Item_in_subselect($1, $5)); }
+        | bit_expr IN_SYM '(' expr ')'
+          {
+              $$= new Item_func_eq($1, $4);
+          }
+	| bit_expr IN_SYM '(' expr ',' expr_list ')'
 	  { 
-            if ($4->elements == 1)
-              $$= new Item_func_eq($1, $4->head());
-            else
-            {
-              $4->push_front($1);
-              $$= new Item_func_in(*$4);
-            }
+              $6->push_front($4);
+              $6->push_front($1);
+              $$= new Item_func_in(*$6);
           }
-	| bit_expr not IN_SYM '(' expr_list ')'
+        | bit_expr not IN_SYM '(' expr ')'
           {
-            if ($5->elements == 1)
-              $$= new Item_func_ne($1, $5->head());
-            else
-            {
-              $5->push_front($1);
-              Item_func_in *item = new Item_func_in(*$5);
+              $$= new Item_func_ne($1, $5);
+          }
+	| bit_expr not IN_SYM '(' expr ',' expr_list ')'
+          {
+              $7->push_front($5);
+              $7->push_front($1);
+              Item_func_in *item = new Item_func_in(*$7);
               item->negate();
               $$= item;
-            }            
           }
-        | bit_expr IN_SYM in_subselect
-	  { $$= new Item_in_subselect($1, $3); }
-	| bit_expr not IN_SYM in_subselect
-          { $$= negate_expression(YYTHD, new Item_in_subselect($1, $4)); }
 	| bit_expr BETWEEN_SYM bit_expr AND_SYM predicate
 	  { $$= new Item_func_between($1,$3,$5); }
 	| bit_expr not BETWEEN_SYM bit_expr AND_SYM predicate
@@ -4329,6 +4330,10 @@ simple_expr:
 	| '-' simple_expr %prec NEG	{ $$= new Item_func_neg($2); }
 	| '~' simple_expr %prec NEG	{ $$= new Item_func_bit_neg($2); }
 	| not2 simple_expr %prec NEG	{ $$= negate_expression(YYTHD, $2); }
+	| '(' subselect ')'   
+          { 
+            $$= new Item_singlerow_subselect($2); 
+          }
 	| '(' expr ')'		{ $$= $2; }
 	| '(' expr ',' expr_list ')'
 	  {
@@ -4340,8 +4345,10 @@ simple_expr:
 	    $5->push_front($3);
 	    $$= new Item_row(*$5);
 	  }
-	| EXISTS exists_subselect { $$= $2; }
-	| singlerow_subselect   { $$= $1; }
+	| EXISTS '(' subselect ')' 
+          {
+            $$= new Item_exists_subselect($3); 
+          }
 	| '{' ident expr '}'	{ $$= $3; }
         | MATCH ident_list_arg AGAINST '(' bit_expr fulltext_options ')'
           { $2->push_front($5);
@@ -6319,14 +6326,17 @@ table_wild_one:
 	ident opt_wild opt_table_alias
 	{
 	  if (!Select->add_table_to_list(YYTHD, new Table_ident($1), $3,
-					 TL_OPTION_UPDATING, Lex->lock_option))
+					 TL_OPTION_UPDATING | 
+                                         TL_OPTION_ALIAS, Lex->lock_option))
 	    YYABORT;
         }
 	| ident '.' ident opt_wild opt_table_alias
 	  {
 	    if (!Select->add_table_to_list(YYTHD,
 					   new Table_ident(YYTHD, $1, $3, 0),
-					   $5, TL_OPTION_UPDATING,
+					   $5, 
+                                           TL_OPTION_UPDATING | 
+                                           TL_OPTION_ALIAS,
 					   Lex->lock_option))
 	      YYABORT;
 	  }
@@ -7545,6 +7555,7 @@ keyword:
 	| TRUNCATE_SYM		{}
 	| UNICODE_SYM		{}
         | XA_SYM                {}
+        | UPGRADE_SYM           {}
 	;
 
 /*
@@ -8867,49 +8878,38 @@ union_option:
 	| ALL       { $$=0; }
         ;
 
-singlerow_subselect:
-	subselect_start singlerow_subselect_init
-	subselect_end
-	{
-	  $$= $2;
-	};
-
-singlerow_subselect_init:
-	select_init2
-	{
-	  $$= new Item_singlerow_subselect(Lex->current_select->
-					   master_unit()->first_select());
-	};
-
-exists_subselect:
-	subselect_start exists_subselect_init
-	subselect_end
-	{
-	  $$= $2;
-	};
-
-exists_subselect_init:
-	select_init2
-	{
-	  $$= new Item_exists_subselect(Lex->current_select->master_unit()->
-					first_select());
-	};
-
-in_subselect:
-  subselect_start in_subselect_init
-  subselect_end
-  {
-    $$= $2;
-  };
+subselect:
+        SELECT_SYM subselect_start subselect_init subselect_end
+        {
+          $$= $3;
+        }
+        | '(' subselect_start subselect ')'
+          {
+            LEX *lex= Lex;
+	    THD *thd= YYTHD;
+            /*
+              note that a local variable can't be used for
+              $3 as it's used in local variable construction
+              and some compilers can't guarnatee the order
+              in which the local variables are initialized.
+            */
+            List_iterator<Item> it($3->item_list);
+            Item *item;
+            /*
+              we must fill the items list for the "derived table".
+            */
+            while ((item= it++))
+              add_item_to_list(thd, item);
+          }
+          union_clause subselect_end { $$= $3; };
 
-in_subselect_init:
+subselect_init:
   select_init2
   {
     $$= Lex->current_select->master_unit()->first_select();
   };
 
 subselect_start:
-	'(' SELECT_SYM
 	{
 	  LEX *lex=Lex;
           if (lex->sql_command == (int)SQLCOM_HA_READ ||
@@ -8918,17 +8918,25 @@ subselect_start:
             yyerror(ER(ER_SYNTAX_ERROR));
 	    YYABORT;
 	  }
+          /* 
+            we are making a "derived table" for the parenthesis
+            as we need to have a lex level to fit the union 
+            after the parenthesis, e.g. 
+            (SELECT .. ) UNION ...  becomes 
+            SELECT * FROM ((SELECT ...) UNION ...)
+          */
 	  if (mysql_new_select(Lex, 1))
 	    YYABORT;
 	};
 
 subselect_end:
-	')'
 	{
 	  LEX *lex=Lex;
           lex->pop_context();
+          SELECT_LEX *child= lex->current_select;
 	  lex->current_select = lex->current_select->return_after_parsing();
           lex->nest_level--;
+          lex->current_select->n_child_sum_items += child->n_sum_items;
 	};
 
 /**************************************************************************