--- Percona-Server-5.1.59/sql/item_cmpfunc.cc	2011-08-11 21:52:53.000000000 +0800
+++ Percona-Server-5.1.59-debug/sql/item_cmpfunc.cc	2011-11-30 21:12:23.000000000 +0800
@@ -506,14 +506,20 @@
           !(field_item->is_datetime() &&
             args[1]->result_type() == STRING_RESULT))
       {
-        if (convert_constant_item(thd, field_item, &args[1]))
-        {
-          cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
-                           INT_RESULT);		// Works for all types.
-          args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
-          return;
-        }
-      }
+		  if ( (!(field_item->field->type() == MYSQL_TYPE_LONGLONG && args[1]->real_item()->type() == DECIMAL_ITEM))
+				  &&	convert_constant_item(thd, field_item, &args[1]))
+		  {
+			  cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
+					  INT_RESULT);		// Works for all types.
+			  args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
+			  return;
+		  } else {
+			  cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
+					  DECIMAL_RESULT);		// Works for all types.
+			  args[0]->cmp_context= args[1]->cmp_context= DECIMAL_RESULT;
+			  return;
+		  }
+	  }
     }
     if (args[1]->real_item()->type() == FIELD_ITEM)
     {
@@ -522,14 +528,20 @@
           !(field_item->is_datetime() &&
             args[0]->result_type() == STRING_RESULT))
       {
-        if (convert_constant_item(thd, field_item, &args[0]))
-        {
-          cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
-                           INT_RESULT); // Works for all types.
-          args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
-          return;
-        }
-      }
+		  if ( (!(field_item->field->type() == MYSQL_TYPE_LONGLONG && args[0]->real_item()->type() == DECIMAL_ITEM))  
+				  &&  convert_constant_item(thd, field_item, &args[0]))
+		  {
+			  cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
+					  INT_RESULT); // Works for all types.
+			  args[0]->cmp_context= args[1]->cmp_context= INT_RESULT;
+			  return;
+		  } else {
+			  cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
+					  DECIMAL_RESULT);		// Works for all types.
+			  args[0]->cmp_context= args[1]->cmp_context= DECIMAL_RESULT;
+			  return;
+		  }
+	  }
     }
   }
   set_cmp_func();