Return Repr-Digest header in compact index

[martinemde]

Supports rubygems/rubygems#7122 with non-deprecated (draft)¹ header for the digest of the full file representation even if only a part of the file is returned. Converts the header to use colon boundaries for byte sequences² in headers.

Footnotes

1. RFC draft (link to Repr-Digest example that distinguishes behavior) ↩

2. RFC 8941 Structured Fields https://www.rfc-editor.org/rfc/rfc8941.html#name-byte-sequences ↩

[simi]

Let's sync somewhere which HTTP Digest headers to support. Also is there any reason to not keep just Digest one for potential backward compatibility?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (0096211) 98.72% compared to head (4a1d33e) 98.72%.
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4174   +/-   ##
=======================================
  Coverage   98.72%   98.72%           
=======================================
  Files         301      301           
  Lines        6822     6822           
=======================================
  Hits         6735     6735           
  Misses         87       87           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[martinemde]

Note: This should change to Repr-Digest.

[martinemde]

@simi, when talking with @segiddins we thought we would leave Digest header for now.

Do you think we should also remove the colons from Digest to keep it identical? Can we safely assume no one is using Digest today that would be impacted?

[martinemde]

I decided to go ahead and convert this to be exactly backwards compatible (thank you recorded Matz).