Partition selector disappears when sorting an empty NestedPartitionedDiskBackedTable

[vbabich]

Run this snippet in Legacy Groovy DHE to open an empty NestedPartitionedDiskBackedTable:

t3 = db.i("LearnDeephaven", "StockQuotes")

Click on a column to sort.

Expected:

• Partition selector stays visible

Actual:

• Partition selector disappears if at least one column is sorted. If I click on the sorted column header twice to reverse and undo the sort, the partition selector shows up again. Sorting a non-empty partitioned table works as expected.

DHE Version 1.20240517.187 (64db4bb6) DHC packages v0.87.0 (tested using npm run start-community)

https://github.com/user-attachments/assets/cccc4824-433d-42dc-a49e-d23b45037d49

[mofojed]

This was on a legacy worker, but I wonder if the table is switching between coalesced/uncoalesced: https://github.com/deephaven/deephaven-core/issues/6210