Details
Major Description
Item::get_copy() and build_clone() may sometimes return an instance of a ancestor class instead of a copy/clone. Look at the example:
class Item
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{
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virtual Item *get_copy(THD *thd)=0;
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}
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class Item_func
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{
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Item *get_copy(THD *thd) override
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{ return get_item_copy<Item_func>(thd, this); }
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}
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classs Item_func_descendant : public Item_func
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{
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// get_copy() not defined, there's no complains from the compiler
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// once it's defined in Item_func
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}
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{
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Item* instance_of_item_func_descendant;
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Item* copy= instance_of_item_func_descendant->get_copy(thd);
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typeid(copy) == "Item_func" although "Item_func_descendant" expected!
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}
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Same refers to Item::build_clone(). A possible solution can be something like this: https://stackoverflow.com/a/9478895/6150050.
Attachments
Issue Links
- causes
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MDEV-34634 Types mismatch when cloning items causes debug assertion
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- Closed
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- relates to
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- Closed
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Activity
| Field | Original Value | New Value |
|---|---|---|
| Description |
Item::get_copy() and build_clone() may sometimes return an instance of a ancestor class instead of a copy/clone. Look at the example:
{code} class Item { virtual Item *get_copy(THD *thd)=0; } class Item_func { Item *get_copy(THD *thd) override { return get_item_copy<Item_func>(thd, this); } } classs Item_func_descendant : public Item_func { // get_copy() not defined, there's no complains from the compiler // once it's defined in Item_func } { Item* instance_of_item_func_descendant; Item* copy= instance_of_item_func_descendant->get_copy(thd); typeid(copy) == "Item_func" although "Item_func_descendant" expected! } {code} Same refers to Item::build_clone(). A possible solution ca be [something like this|https://stackoverflow.com/a/9478895/6150050]. |
Item::get_copy() and build_clone() may sometimes return an instance of a ancestor class instead of a copy/clone. Look at the example:
{code} class Item { virtual Item *get_copy(THD *thd)=0; } class Item_func { Item *get_copy(THD *thd) override { return get_item_copy<Item_func>(thd, this); } } classs Item_func_descendant : public Item_func { // get_copy() not defined, there's no complains from the compiler // once it's defined in Item_func } { Item* instance_of_item_func_descendant; Item* copy= instance_of_item_func_descendant->get_copy(thd); typeid(copy) == "Item_func" although "Item_func_descendant" expected! } {code} Same refers to Item::build_clone(). A possible solution can be something like this: https://stackoverflow.com/a/9478895/6150050. |
| Fix Version/s | 10.5 [ 23123 ] |
| Status | Open [ 1 ] | In Progress [ 3 ] |
| Assignee | Oleg Smirnov [ JIRAUSER50405 ] | Oleksandr Byelkin [ sanja ] |
| Status | In Progress [ 3 ] | In Review [ 10002 ] |
| Assignee | Oleksandr Byelkin [ sanja ] | Oleg Smirnov [ JIRAUSER50405 ] |
| Status | In Review [ 10002 ] | Stalled [ 10000 ] |
| Component/s | Server [ 13907 ] | |
| Fix Version/s | 10.5.26 [ 29832 ] | |
| Fix Version/s | 10.5 [ 23123 ] | |
| Resolution | Fixed [ 1 ] | |
| Status | Stalled [ 10000 ] | Closed [ 6 ] |
| Fix Version/s | 10.6.19 [ 29833 ] | |
| Fix Version/s | 10.11.9 [ 29834 ] | |
| Fix Version/s | 11.1.6 [ 29835 ] | |
| Fix Version/s | 11.2.5 [ 29836 ] | |
| Fix Version/s | 11.4.3 [ 29837 ] |
| Link |
This issue causes |
| Link |
This issue relates to |
sanja, please review the pull request.