fixed a bug where "MATCH ... AGAINST () >=0" was treated as if it was >

sql/sql_select.cc

@@ -1373,13 +1373,13 @@ add_ft_keys(DYNAMIC_ARRAY *keyuse_array,
            functype == Item_func::GT_FUNC)  &&
 	   arg0->type() == Item::FUNC_ITEM          &&
            arg0->functype() == Item_func::FT_FUNC   &&
-           arg1->const_item() && arg1->val()>=0)
+           arg1->const_item() && arg1->val()>0)
         cond_func=(Item_func_match *) arg0;
       else if ((functype == Item_func::LE_FUNC ||
                 functype == Item_func::LT_FUNC)  &&
                 arg1->type() == Item::FUNC_ITEM          &&
                 arg1->functype() == Item_func::FT_FUNC   &&
-                arg0->const_item() && arg0->val()>=0)
+                arg0->const_item() && arg0->val()>0)
         cond_func=(Item_func_match *) arg1;
     }
   }