The fix for MDEV-29352 was pushed to 10.6+ but the code causing the
bug is old and the bug is unlikely to be a recent regression in 10.6.
So, we apply the fix also to older versions, 10.3-10.5.
The original commit message:
MDEV-29352 SIGSEGV's in strlen and unknown location on optimized builds at SHUTDOWN
When the UDF creation frails to write the newly created UDF into
the related system table, the UDF is still created in memory.
However, as it is now, the related DLL is unloaded in this case right
in the mysql_create_function. And failure happens when the UDF handle
is freed and tries to unload the respective DLL which is still unloaded.
When the UDF creation frails to write the newly created UDF into
the related system table, the UDF is still created in memory.
However, as it is now, the related DLL is unloaded in this case right
in the mysql_create_function. And failure happens when the UDF handle
is freed and tries to unload the respective DLL which is still unloaded.
Spider converts HA_READ_KEY_EXACT to the equality (=) in the
function spider_db_append_key_where_internal() but the conversion
is not necessarily correct for tables with prefix indices.
We fix the bug by converting HA_READ_KEY_EXACT to 'LIKE "foo%"' when
a target key is a prefix key. The fix is partly inspired by FEDERATED.
See ha_federated::create_where_from_key() for more details.
ha_spider::field_exchange() returns NULL and that results in a crash
or a assertion failure in spider_db_open_item_ident().
In the first place, there seems to be no need to call field_exchange()
for printing an identity (column name with alias). Thus, we simply
remove the call.
The partition storage engine ignores return (error) values of
handler::info(). As a result, a query that should be aborted is
not aborted and then the server violates the assertion.
Item_func_xor and Item_cond are both derived class of Item_bool_func.
Spider converts *Item_func_xor to *Item_cond and then calls the member
function argument_list(), which Item_func_xor does not implement.
