Gem::RemoteFetcher#fetch_http

# File tmp/rubies/ruby-4.1.0-preview1/lib/rubygems/remote_fetcher.rb, line 224
def fetch_http(uri, last_modified = nil, head = false, depth = 0, headers = self.headers)
  fetch_type = head ? Gem::Net::HTTP::Head : Gem::Net::HTTP::Get
  response   = request uri, fetch_type, last_modified do |req|
    headers.each {|k,v| req.add_field(k,v) }
  end

  case response
  when Gem::Net::HTTPOK, Gem::Net::HTTPNotModified then
    response.uri = uri
    head ? response : response.body
  when Gem::Net::HTTPMovedPermanently, Gem::Net::HTTPFound, Gem::Net::HTTPSeeOther,
       Gem::Net::HTTPTemporaryRedirect, Gem::Net::HTTPPermanentRedirect then
    raise FetchError.new("too many redirects", uri) if depth > 10

    unless location = response["Location"]
      raise FetchError.new("redirecting but no redirect location was given", uri)
    end
    location = uri + location

    if https?(uri) && !https?(location)
      raise FetchError.new("redirecting to non-https resource: #{Gem::Uri.redact(location)}", uri)
    end
    # see Gem::CompactIndexClient::HTTPFetcher#fetch
    same_origin = [location.scheme, location.host, location.port] == [uri.scheme, uri.host, uri.port]
    location.userinfo = uri.userinfo if same_origin && !location.userinfo
    # X-Gemfile-Source carries the source URI that Bundler mirrors,
    # credentials included, and is meant for the mirror's origin only.
    headers = headers.except("X-Gemfile-Source") unless same_origin

    fetch_http(location, last_modified, head, depth + 1, headers)
  else
    custom_error = response["X-Error-Message"]
    error_detail = custom_error || response.message
    raise FetchError.new("Bad response #{error_detail} #{response.code}", uri)
  end
end