The Redirect URL Validation For Applications Is Broken. Please Fix.
Fully qualified host names can be 253 bytes.
The 'Redirect URI' entry (it's really asking for a redirect URL since it needs to know the host) for a new application under 'My Apps' will not allow a valid https://<host>.<domain>/<redirect URI> unless it is quite short.
This is a valid redirect URL in the real world, but the yahoo application page disagrees.
This is a total of 93 characters.
The only URL I could get to work was this:
and that's not a valid redirect URL.. it's a short FQHN.
PLEASE FIX THIS.
The validator also locks up on Firefox and Chrome to the point that it asks if you want to stop the script from running.
Jacek Piszczek commented
Using https://127.0.0.1 for a desktop application no longer works too.