Dolt raises an internal child-count error for CURRENT_TIME(precision)

[Yibo-Dong]

What happened

Dolt exhibits this behavior: CURRENT_TIME(precision) window expression raises an internal child-count error.

Environment

Dolt main (commit c3b5ce3c67f8677ca08a0a58d8c03cdc95bff8b7). MySQL version 8.0.43.

How to reproduce

Run the corresponding SQL in a fresh Dolt repository.

SELECT FIRST_VALUE(LENGTH(CURRENT_TIME(6))) OVER (ROWS BETWEEN CURRENT ROW AND CURRENT ROW) AS length_now,
       FIRST_VALUE(CURRENT_TIME(6)) OVER (ROWS BETWEEN CURRENT ROW AND CURRENT ROW) AS current_time_value;

Expected Result

MySQL 8.0.43 fresh run:

length_now	current_time_value
15	17:35:21.730245

The clock value varies, but the six fractional digits are present and its string length is 15.

Actual Result

The query fails before returning a row:

*function.CurrTime: invalid children number, got 1, expected 0