Error Reading Page Index When Not Available

[tustvold]

Describe the bug

The doc comment for read_pages_locations reads

If not the format not available return an empty vector.

I would take this to mean it would return an empty vector if index information is not available, instead it returns

General("underlying Thrift error: end of file")

To Reproduce

Enable ReadOptions::enable_page_index and try to read a parquet file that lacks a PageIndex

Expected behavior

Enabling the page index shouldn't require it to exist

Additional context