diff options
Diffstat (limited to 'sql/item.cc')
| -rw-r--r-- | sql/item.cc | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/sql/item.cc b/sql/item.cc index 89e23173b0e..4c1fe99e222 100644 --- a/sql/item.cc +++ b/sql/item.cc @@ -1,6 +1,6 @@ /* Copyright (c) 2000, 2018, Oracle and/or its affiliates. - Copyright (c) 2010, 2020, MariaDB Corporation + Copyright (c) 2010, 2020, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -2560,42 +2560,46 @@ bool Type_std_attributes::agg_item_set_converter(const DTCollation &coll, /** @brief Building clone for Item_func_or_sum - + @param thd thread handle - @param mem_root part of the memory for the clone + @param mem_root part of the memory for the clone @details - This method gets copy of the current item and also - build clones for its referencies. For the referencies - build_copy is called again. - - @retval - clone of the item - 0 if an error occurred -*/ + This method first builds clones of the arguments. If it is successful with + buiding the clones then it constructs a copy of this Item_func_or_sum object + and attaches to it the built clones of the arguments. + + @return clone of the item + @retval 0 on a failure +*/ Item* Item_func_or_sum::build_clone(THD *thd) { - Item_func_or_sum *copy= (Item_func_or_sum *) get_copy(thd); - if (unlikely(!copy)) - return 0; + Item *copy_tmp_args[2]= {0,0}; + Item **copy_args= copy_tmp_args; if (arg_count > 2) { - copy->args= - (Item**) alloc_root(thd->mem_root, sizeof(Item*) * arg_count); - if (unlikely(!copy->args)) + copy_args= static_cast<Item**> + (alloc_root(thd->mem_root, sizeof(Item*) * arg_count)); + if (unlikely(!copy_args)) return 0; } - else if (arg_count > 0) - copy->args= copy->tmp_arg; - - for (uint i= 0; i < arg_count; i++) { Item *arg_clone= args[i]->build_clone(thd); - if (!arg_clone) + if (unlikely(!arg_clone)) return 0; - copy->args[i]= arg_clone; + copy_args[i]= arg_clone; + } + Item_func_or_sum *copy= static_cast<Item_func_or_sum *>(get_copy(thd)); + if (unlikely(!copy)) + return 0; + if (arg_count > 2) + copy->args= copy_args; + else if (arg_count > 0) + { + copy->args= copy->tmp_arg; + memcpy(copy->args, copy_args, sizeof(Item *) * arg_count); } return copy; } |