1 files changed, 82 insertions, 55 deletions

diff --git a/sql/item.cc b/sql/item.cc
index 7de32423927..f4b2e549667 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -5063,9 +5063,7 @@ Field *Item::tmp_table_field_from_field_type(TABLE *table, bool fixed_length)
   switch (field_type()) {
   case MYSQL_TYPE_DECIMAL:
   case MYSQL_TYPE_NEWDECIMAL:
-    field= new Field_new_decimal((uchar*) 0, max_length, null_ptr, 0,
-                                 Field::NONE, name, decimals, 0,
-                                 unsigned_flag);
+    field= Field_new_decimal::create_from_item(this);
     break;
   case MYSQL_TYPE_TINY:
     field= new Field_tiny((uchar*) 0, max_length, null_ptr, 0, Field::NONE,
@@ -7182,7 +7180,7 @@ Item_cache* Item_cache::get_cache(const Item *item, const Item_result type)
 {
   switch (type) {
   case INT_RESULT:
-    return new Item_cache_int();
+    return new Item_cache_int(item->field_type());
   case REAL_RESULT:
     return new Item_cache_real();
   case DECIMAL_RESULT:
@@ -7204,8 +7202,9 @@ Item_cache* Item_cache::get_cache(const Item *item, const Item_result type)
 
 void Item_cache::store(Item *item)
 {
-  if (item)
-    example= item;
+  example= item;
+  if (!item)
+    null_value= TRUE;
   value_cached= FALSE;
 }
 
@@ -7219,12 +7218,15 @@ void Item_cache::print(String *str, enum_query_type query_type)
   str->append(')');
 }
 
-void  Item_cache_int::cache_value()
+bool  Item_cache_int::cache_value()
 {
+  if (!example)
+    return FALSE;
   value_cached= TRUE;
   value= example->val_int_result();
   null_value= example->null_value;
   unsigned_flag= example->unsigned_flag;
+  return TRUE;
 }
 
 
@@ -7241,8 +7243,8 @@ void Item_cache_int::store(Item *item, longlong val_arg)
 String *Item_cache_int::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   str->set(value, default_charset());
   return str;
 }
@@ -7251,8 +7253,8 @@ String *Item_cache_int::val_str(String *str)
 my_decimal *Item_cache_int::val_decimal(my_decimal *decimal_val)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   int2my_decimal(E_DEC_FATAL_ERROR, value, unsigned_flag, decimal_val);
   return decimal_val;
 }
@@ -7260,31 +7262,37 @@ my_decimal *Item_cache_int::val_decimal(my_decimal *decimal_val)
 double Item_cache_int::val_real()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0.0;
   return (double) value;
 }
 
 longlong Item_cache_int::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   return value;
 }
 
-void  Item_cache_datetime::cache_value_int()
+bool  Item_cache_datetime::cache_value_int()
 {
+  if (!example)
+    return FALSE;
+
   value_cached= TRUE;
   /* Assume here that the underlying item will do correct conversion.*/
   int_value= example->val_int_result();
   null_value= example->null_value;
   unsigned_flag= example->unsigned_flag;
+  return TRUE;
 }
 
 
-void  Item_cache_datetime::cache_value()
+bool  Item_cache_datetime::cache_value()
 {
+  if (!example)
+    return FALSE;
   str_value_cached= TRUE;
   /* Assume here that the underlying item will do correct conversion.*/
   String *res= example->str_result(&str_value);
@@ -7292,6 +7300,7 @@ void  Item_cache_datetime::cache_value()
     str_value.copy(*res);
   null_value= example->null_value;
   unsigned_flag= example->unsigned_flag;
+  return TRUE;
 }
 
 
@@ -7308,8 +7317,8 @@ void Item_cache_datetime::store(Item *item, longlong val_arg)
 String *Item_cache_datetime::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!str_value_cached)
-    cache_value();
+  if (!str_value_cached && !cache_value())
+    return NULL;
   return &str_value;
 }
 
@@ -7317,8 +7326,8 @@ String *Item_cache_datetime::val_str(String *str)
 my_decimal *Item_cache_datetime::val_decimal(my_decimal *decimal_val)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value_int();
+  if (!value_cached && !cache_value_int())
+    return NULL;
   int2my_decimal(E_DEC_FATAL_ERROR, int_value, unsigned_flag, decimal_val);
   return decimal_val;
 }
@@ -7326,40 +7335,43 @@ my_decimal *Item_cache_datetime::val_decimal(my_decimal *decimal_val)
 double Item_cache_datetime::val_real()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value_int();
+  if (!value_cached && !cache_value_int())
+    return 0.0;
   return (double) int_value;
 }
 
 longlong Item_cache_datetime::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value_int();
+  if (!value_cached && !cache_value_int())
+    return 0;
   return int_value;
 }
 
-void Item_cache_real::cache_value()
+bool Item_cache_real::cache_value()
 {
+  if (!example)
+    return FALSE;
   value_cached= TRUE;
   value= example->val_result();
   null_value= example->null_value;
+  return TRUE;
 }
 
 
 double Item_cache_real::val_real()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0.0;
   return value;
 }
 
 longlong Item_cache_real::val_int()
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   return (longlong) rint(value);
 }
 
@@ -7367,8 +7379,8 @@ longlong Item_cache_real::val_int()
 String* Item_cache_real::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   str->set_real(value, decimals, default_charset());
   return str;
 }
@@ -7377,27 +7389,30 @@ String* Item_cache_real::val_str(String *str)
 my_decimal *Item_cache_real::val_decimal(my_decimal *decimal_val)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   double2my_decimal(E_DEC_FATAL_ERROR, value, decimal_val);
   return decimal_val;
 }
 
 
-void Item_cache_decimal::cache_value()
+bool Item_cache_decimal::cache_value()
 {
+  if (!example)
+    return FALSE;
   value_cached= TRUE;
   my_decimal *val= example->val_decimal_result(&decimal_value);
   if (!(null_value= example->null_value) && val != &decimal_value)
     my_decimal2decimal(val, &decimal_value);
+  return TRUE;
 }
 
 double Item_cache_decimal::val_real()
 {
   DBUG_ASSERT(fixed);
   double res;
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   my_decimal2double(E_DEC_FATAL_ERROR, &decimal_value, &res);
   return res;
 }
@@ -7406,8 +7421,8 @@ longlong Item_cache_decimal::val_int()
 {
   DBUG_ASSERT(fixed);
   longlong res;
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   my_decimal2int(E_DEC_FATAL_ERROR, &decimal_value, unsigned_flag, &res);
   return res;
 }
@@ -7415,8 +7430,8 @@ longlong Item_cache_decimal::val_int()
 String* Item_cache_decimal::val_str(String *str)
 {
   DBUG_ASSERT(fixed);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   my_decimal_round(E_DEC_FATAL_ERROR, &decimal_value, decimals, FALSE,
                    &decimal_value);
   my_decimal2string(E_DEC_FATAL_ERROR, &decimal_value, 0, 0, 0, str);
@@ -7426,14 +7441,16 @@ String* Item_cache_decimal::val_str(String *str)
 my_decimal *Item_cache_decimal::val_decimal(my_decimal *val)
 {
   DBUG_ASSERT(fixed);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   return &decimal_value;
 }
 
 
-void Item_cache_str::cache_value()
+bool Item_cache_str::cache_value()
 {
+  if (!example)
+    return FALSE;
   value_cached= TRUE;
   value_buff.set(buffer, sizeof(buffer), example->collation.collation);
   value= example->str_result(&value_buff);
@@ -7452,6 +7469,7 @@ void Item_cache_str::cache_value()
     value_buff.copy(*value);
     value= &value_buff;
   }
+  return TRUE;
 }
 
 double Item_cache_str::val_real()
@@ -7459,8 +7477,8 @@ double Item_cache_str::val_real()
   DBUG_ASSERT(fixed == 1);
   int err_not_used;
   char *end_not_used;
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0.0;
   if (value)
     return my_strntod(value->charset(), (char*) value->ptr(),
 		      value->length(), &end_not_used, &err_not_used);
@@ -7472,8 +7490,8 @@ longlong Item_cache_str::val_int()
 {
   DBUG_ASSERT(fixed == 1);
   int err;
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   if (value)
     return my_strntoll(value->charset(), value->ptr(),
 		       value->length(), 10, (char**) 0, &err);
@@ -7485,8 +7503,8 @@ longlong Item_cache_str::val_int()
 String* Item_cache_str::val_str(String *str)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   return value;
 }
 
@@ -7494,8 +7512,8 @@ String* Item_cache_str::val_str(String *str)
 my_decimal *Item_cache_str::val_decimal(my_decimal *decimal_val)
 {
   DBUG_ASSERT(fixed == 1);
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return NULL;
   if (value)
     string2my_decimal(E_DEC_FATAL_ERROR, value, decimal_val);
   else
@@ -7506,8 +7524,8 @@ my_decimal *Item_cache_str::val_decimal(my_decimal *decimal_val)
 
 int Item_cache_str::save_in_field(Field *field, bool no_conversions)
 {
-  if (!value_cached)
-    cache_value();
+  if (!value_cached && !cache_value())
+    return 0;
   int res= Item_cache::save_in_field(field, no_conversions);
   return (is_varbinary && field->type() == MYSQL_TYPE_STRING &&
           value->length() < field->field_length) ? 1 : res;
@@ -7542,13 +7560,21 @@ bool Item_cache_row::setup(Item * item)
 
 void Item_cache_row::store(Item * item)
 {
+  example= item;
+  if (!item)
+  {
+    null_value= TRUE;
+    return;
+  }
   for (uint i= 0; i < item_count; i++)
     values[i]->store(item->element_index(i));
 }
 
 
-void Item_cache_row::cache_value()
+bool Item_cache_row::cache_value()
 {
+  if (!example)
+    return FALSE;
   value_cached= TRUE;
   null_value= 0;
   example->bring_value();
@@ -7557,6 +7583,7 @@ void Item_cache_row::cache_value()
     values[i]->cache_value();
     null_value|= values[i]->null_value;
   }
+  return TRUE;
 }