Panic in FFI UDWF when using wrapping lead function

[timsaucer]

Describe the bug

During testing of the initial implementation of FFI user defined window functions, I generated a panic in partition_evaluator.

To Reproduce

Open examples/datafusion-ffi-example/src/window_udf.rs

Change this to use lead_udwf() instead of rank_udwf().

Run integration test in examples/datafusion-ffi-example/python/tests/_test_window_udf.py

Expected behavior

Should not panic.

Additional context

It is unclear if the problem is in datafusion-python, or more likely upstream.

[kosiew]

hi @timsaucer ,

Can you share examples/datafusion-ffi-example/src/window_udf.rs?
I don't believe it's in main yet.

[kosiew]

Never mind, I got the file from #1145

[kosiew]

hi @timsaucer

I can see some errors when I pytest _test_window_udf.py in #1145 but I want to be sure it is the same error as you are reporting in this issue.
Can you share the errors you are seeing?

[timsaucer]

Sorry it took so long to respond. I went to reproduce the error and took a few minutes to dig into this. I found the bug and will be putting up a PR in the upstream repo today.