Item::fix_field need correct pointer on item reference to chnge it if itis need, so support of correct item address added to SP commands (BUG#5963)

some optimisation of IF/NOT IF ptomised to Pem

6 files changed, 76 insertions, 23 deletions

diff --git a/sql/item.cc b/sql/item.cc
index f5c7f2d7c05..ec93480499e 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -740,6 +740,13 @@ Item_splocal::this_item()
   return thd->spcont->get_item(m_offset);
 }
 
+
+Item **
+Item_splocal::this_item_addr(THD *thd, Item **addr)
+{
+  return thd->spcont->get_item_addr(m_offset);
+}
+
 Item *
 Item_splocal::this_const_item() const
 {
diff --git a/sql/item.h b/sql/item.h
index 697194e2878..ab8059b8fd1 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -525,8 +525,17 @@ public:
   virtual Item *equal_fields_propagator(byte * arg) { return this; }
   virtual Item *set_no_const_sub(byte *arg) { return this; }
   virtual Item *replace_equal_field(byte * arg) { return this; }
-  
-  virtual Item *this_item() { return this; } /* For SPs mostly. */
+
+  /*
+    For SP local variable returns pointer to Item representing its
+    current value and pointer to current Item otherwise.
+  */
+  virtual Item *this_item() { return this; }
+  /*
+    For SP local variable returns address of pointer to Item representing its
+    current value and pointer passed via parameter otherwise.
+  */
+  virtual Item **this_item_addr(THD *thd, Item **addr) { return addr; }
   virtual Item *this_const_item() const { return const_cast<Item*>(this); } /* For SPs mostly. */
 
   // Row emulation
@@ -573,6 +582,7 @@ public:
   bool is_splocal() { return 1; } /* Needed for error checking */
 
   Item *this_item();
+  Item **this_item_addr(THD *thd, Item **);
   Item *this_const_item() const;
 
   bool fix_fields(THD *, struct st_table_list *, Item **);
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index 9fb4b1c7fac..1b336278f07 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -97,19 +97,48 @@ sp_multi_results_command(enum enum_sql_command cmd)
   }
 }
 
+
+/*
+  Prepare Item for execution (call of fix_fields)
+
+  SYNOPSIS
+    sp_prepare_func_item()
+    thd       thread handler
+    it_addr   pointer on item refernce
+
+  RETURN
+    NULL  error
+    prepared item
+*/
+
+static Item *
+sp_prepare_func_item(THD* thd, Item **it_addr)
+{
+  Item *it= *it_addr;
+  DBUG_ENTER("sp_prepare_func_item");
+  it_addr= it->this_item_addr(thd, it_addr);
+
+  if (!it->fixed && (*it_addr)->fix_fields(thd, 0, it_addr))
+  {
+    DBUG_PRINT("info", ("fix_fields() failed"));
+    DBUG_RETURN(NULL);
+  }
+  DBUG_RETURN(*it_addr);
+}
+
+
 /* Evaluate a (presumed) func item. Always returns an item, the parameter
 ** if nothing else.
 */
 Item *
-sp_eval_func_item(THD *thd, Item *it, enum enum_field_types type)
+sp_eval_func_item(THD *thd, Item **it_addr, enum enum_field_types type)
 {
   DBUG_ENTER("sp_eval_func_item");
-  it= it->this_item();
+  Item *it= sp_prepare_func_item(thd, it_addr);
   DBUG_PRINT("info", ("type: %d", type));
 
-  if (!it->fixed && it->fix_fields(thd, 0, &it))
+  if (!it)
   {
-    DBUG_PRINT("info", ("fix_fields() failed"));
     DBUG_RETURN(NULL);
   }
 
@@ -678,7 +707,7 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
   for (i= 0 ; i < params && i < argcount ; i++)
   {
     sp_pvar_t *pvar = m_pcont->find_pvar(i);
-    Item *it= sp_eval_func_item(thd, *argp++, pvar->type);
+    Item *it= sp_eval_func_item(thd, argp++, pvar->type);
 
     if (it)
       nctx->push_item(it);
@@ -760,7 +789,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
   {
     Item_null *nit= NULL;	// Re-use this, and only create if needed
     uint i;
-    List_iterator_fast<Item> li(*args);
+    List_iterator<Item> li(*args);
     Item *it;
 
     nctx= new sp_rcontext(csize, hmax, cmax);
@@ -793,7 +822,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
 	}
 	else
 	{
-	  Item *it2= sp_eval_func_item(thd, it, pvar->type);
+	  Item *it2= sp_eval_func_item(thd, li.ref(), pvar->type);
 
 	  if (it2)
 	    nctx->push_item(it2); // IN or INOUT
@@ -1438,7 +1467,7 @@ sp_instr_set::exec_core(THD *thd, uint *nextp)
   Item *it;
   int res;
 
-  it= sp_eval_func_item(thd, m_value, m_type);
+  it= sp_eval_func_item(thd, &m_value, m_type);
   if (! it)
     res= -1;
   else
@@ -1568,13 +1597,13 @@ sp_instr_jump_if::exec_core(THD *thd, uint *nextp)
   Item *it;
   int res;
 
-  it= sp_eval_func_item(thd, m_expr, MYSQL_TYPE_TINY);
+  it= sp_prepare_func_item(thd, &m_expr);
   if (!it)
     res= -1;
   else
   {
     res= 0;
-    if (it->val_int())
+    if (it->val_bool())
       *nextp = m_dest;
     else
       *nextp = m_ip+1;
@@ -1626,13 +1655,13 @@ sp_instr_jump_if_not::exec_core(THD *thd, uint *nextp)
   Item *it;
   int res;
 
-  it= sp_eval_func_item(thd, m_expr, MYSQL_TYPE_TINY);
+  it= sp_prepare_func_item(thd, &m_expr);
   if (! it)
     res= -1;
   else
   {
     res= 0;
-    if (! it->val_int())
+    if (! it->val_bool())
       *nextp = m_dest;
     else
       *nextp = m_ip+1;
@@ -1684,7 +1713,7 @@ sp_instr_freturn::exec_core(THD *thd, uint *nextp)
   Item *it;
   int res;
 
-  it= sp_eval_func_item(thd, m_value, m_type);
+  it= sp_eval_func_item(thd, &m_value, m_type);
   if (! it)
     res= -1;
   else
diff --git a/sql/sp_rcontext.cc b/sql/sp_rcontext.cc
index def38009eee..672491a97f2 100644
--- a/sql/sp_rcontext.cc
+++ b/sql/sp_rcontext.cc
@@ -41,10 +41,10 @@ sp_rcontext::sp_rcontext(uint fsize, uint hmax, uint cmax)
 }
 
 int
-sp_rcontext::set_item_eval(uint idx, Item *i, enum_field_types type)
+sp_rcontext::set_item_eval(uint idx, Item **item_addr, enum_field_types type)
 {
-  extern Item *sp_eval_func_item(THD *thd, Item *it, enum_field_types type);
-  Item *it= sp_eval_func_item(current_thd, i, type);
+  extern Item *sp_eval_func_item(THD *thd, Item **it, enum_field_types type);
+  Item *it= sp_eval_func_item(current_thd, item_addr, type);
 
   if (! it)
     return -1;
diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index afcd937a369..c132032e32c 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -74,7 +74,7 @@ class sp_rcontext : public Sql_alloc
 
   /* Returns 0 on success, -1 on (eval) failure */
   int
-  set_item_eval(uint idx, Item *i, enum_field_types type);
+  set_item_eval(uint idx, Item **i, enum_field_types type);
 
   inline Item *
   get_item(uint idx)
@@ -82,6 +82,14 @@ class sp_rcontext : public Sql_alloc
     return m_frame[idx];
   }
 
+
+  inline Item **
+  get_item_addr(uint idx)
+  {
+    return m_frame + idx;
+  }
+
+
   inline void
   set_result(Item *it)
   {
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index a6a1f4d60ef..2d5c4722164 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -1719,10 +1719,9 @@ bool select_dumpvar::send_data(List<Item> &items)
   List_iterator_fast<Item_func_set_user_var> li(vars);
   List_iterator_fast<Item_splocal> var_li(local_vars);
   List_iterator_fast<my_var> my_li(var_list);
-  List_iterator_fast<Item> it(items);
+  List_iterator<Item> it(items);
   Item_func_set_user_var *xx;
   Item_splocal *yy;
-  Item *item;
   my_var *zz;
   DBUG_ENTER("send_data");
   if (unit->offset_limit_cnt)
@@ -1741,13 +1740,13 @@ bool select_dumpvar::send_data(List<Item> &items)
     my_message(ER_TOO_MANY_ROWS, ER(ER_TOO_MANY_ROWS), MYF(0));
     DBUG_RETURN(1);
   }
-  while ((zz=my_li++) && (item=it++))
+  while ((zz=my_li++) && (it++))
   {
     if (zz->local)
     {
       if ((yy=var_li++)) 
       {
-	if (thd->spcont->set_item_eval(yy->get_offset(), item, zz->type))
+	if (thd->spcont->set_item_eval(yy->get_offset(), it.ref(), zz->type))
 	  DBUG_RETURN(1);
       }
     }