Yeah, this is pretty straight forward. When you run "git cl patch", if your branch already has branch-specific configuration for Gerrit or Rietveld, it'll use the appropriate system to download the patch.

If you don't (which is the default case for a new branch), then it defaults to the one that it reads out of codereview.settings, which now specified Gerrit.

Unfortunately, Gerrit and Rietveld URLs (without whitelisting specific hosts) look very similar, so it things that codereview.chromium.org is a Gerrit host, tries to use the Gerrit API, and fails.

Not sure whether the best solution is to git "git cl patch" --gerrit/--rietveld flags, or to make both implementations fall back to the other impl, or to hoist them both up to the parent class impl which could then try each in sequence.

I'd say use --rietveld very short term OR copy-paste URL with patchset number in it, this is unique enough to Rietveld and it definitely used to work before.

Medium term - maybe have special case for 3 typical urls:
codereview.chromium.org
codereview.webrtc.org
codereview.appspot.com
s.t. they are treated as if they were Rietveld.

and long term Rietveld is no longer supported :)

The point is that using the URL doesn't work, because we don't whitelist Rietveld hosts. We *could* (as you suggest), but note that we'd also have to whitelist internal Rietveld hosts.

I don't see a problem in whitelisting internal Rietveld hosts, it's not like the domain names are private anyway :)

 Issue 667341  has been merged into this issue.

Issue 667927 has been merged into this issue.

As of https://chromium.googlesource.com/chromium/tools/depot_tools/+/c2786d933bb6517a88ba6ff95e1606f656d89178, "git cl patch --gerrit <url>" works, as does "git cl patch --rietveld <url>".

Since the flag exists, I have no plans to whitelist specific hosts. Just use the flag.