Okay, here's a tentative plan to attack this:

• Do T4245.
• Add an alternate rendering method like "getCommitNameInUnambiguousContext()" (maybe this is a flag or something).
• That method renders the identifier only if the repository has no callsign.
• You remove all your callsigns.

They'd break, as would all existing URLs referencing /diffusion/X/. However, the UIs would become pretty, so this seems like a small price to pay.

Wait, so in this situation, would the urls be /diffusion/23/?

I think that's uglier than using the callsigns. We already enforce our repository names to be url-safe, and we would like to use the names in urls and remotes (we already have a hack in place that let's us clone git@phabricator.company.com:RepositoryName). We think that this conveys much more context and is clearer than arbitrary callsigns.

For example:

• http://phabricator.company.com/diffusion/SR/browse/master/composer.json
• git clone git@phabricator.company.com:diffusion/SR
  • This is alright, but we think it's ugly.
• http://phabricator.company.com/diffusion/23/browse/master/composer.json
• git clone git@phabricator.company.com:diffusion/23
  • This is even worse, as even less information is conveyed.
• http://phabricator.company.com/diffusion/SecretReposotory/browse/master/composer.json
• git clone git@phabricator.company.com:diffusion/SecretRepository or git clone git@phabricator.company.com:SecretRepository
  • This is ideally what we would want.

As far as linking to commits, (at least for us) in most situations, just the hash is enough. If you do have duplicate hashes, R23:abc12345 or something (as mentioned in T4245) to identify "I mean this repository" should be fine. Upon second though, in our example above, the user would have no way of knowing what the ID of the repository is. If the repository names are url safe, it's pretty trivial to do SecretProject@abc1234

In reference to the UIs becoming pretty, almost all of the items and pictures I listed above, the callsign could be removed now, before T4245 is done. The callsign in all of those is redundant, it's already clear which repo we are talking about. There are already places in the ui where we reference commits by the revision id with no callsign, specifically when looking at blame:

The remarkup-friendly commit hash (with the preceding 'r' and callsign) is (most likely) shown all over the UI there to make it easy for users to copy and know how to reference them elsewhere - I doubt anyone thinks you need to be constantly reminded what repo you're looking at several times per page.