MySQL Bugs: #97288: function execution 2 or 3 times crash the server

Bug #97288	function execution 2 or 3 times crash the server
Submitted:	18 Oct 2019 13:04	Modified:	18 Oct 2019 13:52
Reporter:	Franco Pellegrini	Email Updates:
Status:	Unsupported	Impact on me:	None
Category:	MySQL Server: User-defined functions ( UDF )	Severity:	S1 (Critical)
Version:	10.4.8-MariaDB	OS:	Windows (10)
Assigned to:		CPU Architecture:	x86 (64)
Tags:	cash, FUNCTION, server

Description:
If I execute more than one time this function, the server crash with no errors.
The function try to search 2 columns in 2 tables, and return true if they exists on both tables.

How to repeat:
execute manually 2 or 3 times this function (in short period of time)

CREATE FUNCTION if_column_exists_normal_and_backup(tableNameToSearch TINYTEXT,
                                                   columnNameToSearch TINYTEXT)
    RETURNS BOOLEAN
    LANGUAGE SQL
BEGIN
    SET @original = tableNameToSearch;
    SET @backup = CONCAT(tableNameToSearch, '_backup');

    RETURN (
            exists(SELECT COLUMN_NAME
                   FROM INFORMATION_SCHEMA.COLUMNS
                   WHERE TABLE_NAME = @original
                     AND COLUMN_NAME = `columnnametosearch`
                )
            AND
            exists(SELECT COLUMN_NAME
                   FROM INFORMATION_SCHEMA.COLUMNS
                   WHERE TABLE_NAME = @backup
                     AND COLUMN_NAME = `columnnametosearch`
                )
        );
END

Thank you for the bug report. The server version reported isn't supported, try with an Oracle MySQL server and report again if happens the issue too.

Please, either check if any recent MySQL version (like 8.0.18) is also affected, or report this to MariaDB: https://jira.mariadb.org