Org to Org migration and URL renaming

[thorntonryan]

@timrogers , follow up question to #809

@thorntonryan Thanks for your patience on this! The answer to this question is a little complicated, so I'll break it down step by step:

• If you use the "short permalink" style (e.g. org/repo#), and the name of the organization and repo is the same after the migration as it was before the migration, then those links will continue to work.
• If you use the "short permalink" style (e.g. org/repo#) or a full URL and you run an organization-to-organization migration (see the docs, only available when migrating from GitHub.com to GitHub.com), then we will rewrite the URLs to match your new GitHub host, organization and repo name.
• In all other cases, links will not be re-written during a migration.

I hope that helps! If you have any further questions, or if you think I've made any mistakes, then do feel free to let me know.

Supposing we run an org to org migration and go from something like:

my.enterprise.github.com/myorg/repo => github.com/myenterprise_myorg/repo

If I follow, based on your second bullet point, the migration utility is expected to rewrite these short permalinks or short urls to point at the new org... correct?

If that's true, then I have a follow up question:
If we do an org-to-to org migration, then once we're on github.com... can we migrate that repo to a different org and get URLs re-written a second time?

github.com/myenterprise_org/repo ==> github.com/myenterprise_other_org/repo

For "reasons", we might have a decent use case for an org to org migration, but I'm wondering if we two-step our migrations -- doing org-to-org then another move internally within github, if that would effectively help handling URL re-writing spanning where the org changes
(something that isn't directly supported as outlined by #809)