Created attachment 606532 [details] [diff] [review] WIP To test this, apply the patch from bug 735215, create an XMPP account, then remove the patch from bug 735215. The handling of this edge case doesn't have to be perfect, but I think it should at least be good enough for an user to be able to delete a leftover account. The attached patch significantly improves the situation (the Account Settings dialog can display correctly the pane related to the account without protocol plugin), but removing the account doesn't fully work (some preferences are still there after a restart) so I'm not requesting a review yet.
Created attachment 634395 [details] [diff] [review] Patch Requesting review from David for the Thunderbird account settings part (files in mail/components/im) and Patrick for the chat/ file.
Comment on attachment 634395 [details] [diff] [review] Patch All my review comments were already given over IRC @ http://log.bezut.info/instantbird/120619/#m259 and fixed before this version.
Comment on attachment 634395 [details] [diff] [review] Patch this looks reasonable, though the variable name "protocol" is so much more clear than "proto", especially in js code :-)
Comment on attachment 634395 [details] [diff] [review] Patch [Approval Request Comment] User impact if declined: If users install additional protocol plugins as add-ons, and for some reason the add-on is no longer available (uninstalled by the user, incompatible with a newer version of Thunderbird, ...) it's impossible to delete the left-over chat account without this patch.