Incorrect identification and reporting of HTTP Redirection

[piersoh]

Environment

• The MPD passes the DASH-IF Conformance Tool on https://conformance.dashif.org/
• The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream
• The issue observed is not mentioned on https://github.com/Dash-Industry-Forum/dash.js/wiki/FAQ
• The issue occurs in the latest reference client on http://reference.dashif.org/dash.js/ and not just on my page

• Link to playable MPD file:
• Dash.js version: dash.js since 2016
• Browser name/version: Any
• OS name/version: Any

Steps to reproduce

1. Load MPD with Metrics Reporting enabled
2. Activate CMCD

Observed behavior

1. Dash.js incorrectly identifies all requests as "redirected" here:
   

   dash.js/src/streaming/models/MetricsModel.js

   Line 148 in 59548dd

   if (actualurl && (actualurl !== url)) {

• This is fixed by Set response.url to modifiedUrl #3720 so that the "modifiedUrl" is passed on so it is firstly correctly reported and secondly so it no longer identifies it as "redirect".

2. It correctly logs two HttpList entries (if enabled)
3. It incorrectly generates a C03 for every "redirected" request

• This due to the fact that null is passed as the status to the second addHttpRequest() call, which leads to an error report. Though a null status is currently only caught by accident (Fixed in Explicitly match null status #3722).

Expected behavior

This then leads a question as to how to correctly identify and handle redirects

• With XHR it was only possible to compare the actualurl with the url, whereas with Fetch there is an explicit parameter (response.redirected) which indicates that redirection has occured. But in both cases the actual HTTP redirection response code is unknown so it's not clear what status to report either:
  • one just generates a second [largely blank] HttpList as is done now
  • Or the second HttpList report is just dropped and the client only adds the actualurl to reports when it detects a redirection so a logging server can infer that from the presence of actualurl. DVB Spec says actualurl only needs to be reported if different from url.

[dsilhavy]

@piersoh Thanks for reporting this. Is this something you can look into further? I would prefer the second approach you described above. Adding the actualurl in case there was a redirect.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. However, it might still be relevant so please leave a short comment if it should remain open. Otherwise the issue will be closed automatically after two weeks. Thank you for your contributions.

[stale]

This issue has been automatically closed because no further activity occurred. If you think this issue is still relevant please reopen it or contact @dsilhavy. Thank you for your contributions.