False cache hits leading to corrupt downloads

[jeroen]

A user of the r bindings reported weird behavior when downloading a file https://openml.org/data/v1/download/16797613/CIFAR_10.arff

After some testing I think I see the bug: you are using a server-side cache which seems to not understand the Vary: Accept-Encoding header that you use to key the cache.

As a result, the cache server is sending cached responses that are compressed with gzip or brotli to clients that do not support it, or at least did not request this in the Accept-Encoding request header, and hence are not decompressing it.

I confirmed the problem goes away when you add some random ?nocache=1234 parameter to the URL to force bypassing the cache.

[PGijsbers]

Thanks for the report, Jeroen! We'll investigate.