[SPARK-27778][PYTHON] Fix toPandas conversion of empty DataFrame with Arrow enabled #625
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What changes were proposed in this pull request?
apache#22275 introduced a performance improvement where we send partitions out of order to python and then, as a last step, send the partition order as well.
However, if there are no partitions we will never send the partition order and we will get an "EofError" on the python side.
This PR fixes this by also sending the partition order if there are no partitions present.
How was this patch tested?
New unit test added.