Trying to make a private team public crashes if it has a mailing list

[Ursula Junque]

It's not possible to make a team public if it has a mailing list. When trying to do that, as seen in OOPS-1048EB219, the exception is not caught, and it crashes with:

Steps to reproduce (using launchpad.dev):
1. Open https://launchpad.dev/~name21/+edit
2. Make it a private team (change visibility to Private Membership)
3. Request a mailing list for the team (https://launchpad.dev/~name21/+mailinglist)
4. Approve the mailing list (https://launchpad.dev/+mailinglists)
5. Change the visibility to Public (https://launchpad.dev/~name21/+edit)
6. OOPS-1048EB216 (ValueError: This team cannot be made public since it has a mailing list)

What should happen: A nice error message displayed to the user explaining why the team can't be made public

[Curtis Hovey (sinzui)]

This may be a cherry pickable items; its status may be critical.

[Curtis Hovey (sinzui)]

Bug 298224 may be a duplicate.

[Christian Reis (kiko)]

I'm not sure. The thing is, I get a proper error message in bug 298224 -- not an OOPS. Barry could probably fix both together though.

[Barry Warsaw (barry)]

I am.