WEBrick's not_modified? treats a Range request's If-Range header like
If-None-Match, replying 304 with no body instead of 206 with the
requested bytes. Browsers rely on this to fetch a video's trailing
moov atom, so jekyll serve was breaking playback for videos recorded
with metadata at the end of the file. Dev-server-only; production is
unaffected since it isn't served by WEBrick.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Thomas Quinot