Description:
After component_query_attributes is installed, mysql_query_attribute_string accepts a numeric argument even though the function requires a string argument. The function executes, returns SQL NULL, and produces no warning.
Actual result:
mysql_query_attribute_string(12345)
NULL
SHOW WARNINGS returns no rows.
Expected result:
The SELECT should fail during UDF initialization with the component's “expects a string argument” diagnostic because 12345 is numeric.
Impact:
Applications can pass an invalid argument type without receiving an error or warning. The resulting NULL is indistinguishable from an ordinary NULL result and can mask query defects.
Tested versions:
MySQL Community Server 9.7.2 and 26.7.0. The behavior reproduced on both versions.
Environment and configuration:
Linux x86-64. Source commit e174239c5b3c2bcf164649042ab8a7fc972ce88d. component_query_attributes was installed before invoking the function.
How to repeat:
INSTALL COMPONENT 'file://component_query_attributes';
SELECT mysql_query_attribute_string(12345);
SHOW WARNINGS;
Suggested fix:
Return the UDF initialization failure value when a non-string argument is detected so execution is rejected.
