There is a second layer to the bug in that github pages should almost certainly not be sending back slices of compressed files even if gzip is listed before identity and some change to something in the github stack probably exposed the bug that was there in firefox all along.
I literally just stumbled on this last week while doing a side project that involved browser range requests so this is fresh in my head.
1. it comes down to whether it was meant that 'Accept-Encoding:identity' should be appended to the list of header values possibly overwriting the one that already was there or if 'identity' should be appended to the list of values already in the 'Accept-Encoding' header. Firefox does the latter, everyone else does the former.
https://github.com/seligman/podcast_to_text/blob/master/sear...
In my case, loading the entire file is loading a tiny bit more data, so this fallback doesn't hurt, but it's still annoying, and broke any hope I had of doing something more clever with the dataset.