General: Mixed-case domain names cause connection issues?

[aheckler]

I have a test site with settings like so:

Note the capital letters in the domain. When I connect that to WP.com, our debugger returns an unknown error:

http://jetpack.me/support/debug/?url=http%3A%2F%2Ftestingcapdomain.nfshost.com%2F

... and I can't update plugins from WP.com:

My in-dash debug links says everything is OK though:

The old debugger returns: "-10520: Jetpack: [invalid_signature] The required "url" parameter is malformed."

To repro, just connect a site to JP with the Site and Home URL as mixed case.

[dereksmart]

I can't reproduce. Did you try this on any other hosts?

[aheckler]

Happened for me on NearlyFreeSpeech.NET and the user who brought this to my attention (in 2200215-t) is on BlueHost. I can maybe screenshare with you at some point and walk you through it if you want.

[dereksmart]

After extensive debugging and testing, we've learned a few things:

• The debugger had a minor glitch (fixed dotcom side)
• update failures from dotcom were because FTP creds were required (fix is to set the creds in wp-config)
• mixed case domains inherently don't cause any problems.