download_attachment.php always streamed the entire file regardless of
any Range request header, and never advertised Accept-Ranges. Large
video/PDF attachments couldn't be scrubbed in-browser, and an
interrupted download had to restart from byte 0.
Now parses a single-range "bytes=start-end" (including open-ended and
suffix forms) request header and responds with 206 Partial Content and
a Content-Range header, seeking the file handle to the requested
offset; out-of-range requests get 416 with Content-Range: bytes
*/<size>. Verified against a real file served over a local PHP dev
server with curl for exact-range, open-ended, suffix, no-Range, and
out-of-bounds cases, confirming byte-identical output for each.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015nCxwFFsy8ouMWzn56rPVP
jaredandClaude Sonnet 5
b0765eb7f4