Google Contacts 0.3.40 is now available for download. In this version, you can undo deletion of contacts. Since the addon is untable yet, it may delete contacts in Google by a bug. You may delete them by mistake, too. You can recover the deleted contacts/groups by using this new functionality.
You can invoke the function from a drop down menu of the Reload button in the address book window (see the image). The Reload button is not added by default settings. Customize the toolbar and add the icon if you have not added it yet.
There are a few limitaions:
- only Google entries deleted from the address book window can be recovered
- a mail list can be recovered but email addresses which are stored in it are not restored
- only entries deleted in the session will be restored; i.e, all cache are purged when you finish Thunderbird