Make a blog in Phame and assign a CNAME, for example, `blog.foo.com`.
Next, make a post, and link to a repository (or another object) inside your post - for example, by mentioning rP or rPHU.
Now, if you look at these hyperlinks, they will be incorrectly routed to the blog CNAME, *not* the original Phabricator URL. In other words:
- If your blog does not have a CNAME, `rFOO` links to `/diffusion/FOO` correctly.
- If your blog *does* have a CNAME (`blog.foo.com`), `rFOO` links to `/diffusion/FOO` - but this is wrong, because the relative URL is now `blog.foo.com`, making the whole URL `blog.foo.com/diffusion/FOO`
The fix basically is:
- If an object is referenced by a post,
- AND a CNAME is set,
- The hyperlink must instead point to the FQDN of the object, not the relative URL.