1. With a new profile, tag a page with one or more tags. 2. Restart Firefox in safe mode. Check "Reset Bookmarks to Minefield defaults" and click "Make Changes and Restart". Open the Library and you'll see all your tags, which aren't tagging anything.

Marco, would this cause any trouble?

This will need an update of https://litmus.mozilla.org/show_test.cgi?id=6931

ideally no, i cannot tell offhand if there is some obscure bug that could be awaken by childless tags... btw preventive maintenance for now will take care of them. The "Reset bookmarks" case probably runs while tagging service does not exist, so they are not removed.

That means those tags are not listed under Tags? What will happen if someone want to create such a tag which already exists. Will that be possible or is it prevented because an already existing tag exists? Both questions are limited to before the maintenance task will be run.

afaict tags will be shown empty in the Library, user should still be able to use them.

Tested and it works. One thing I have discovered by quickly checking is when you add again one of the bookmarks you had before the not removed tag is automatically applied to the bookmark.

Bug 451915 - move Firefox/Places bugs to Firefox/Bookmarks and History. Remove all bugspam from this move by filtering for the string "places-to-b-and-h". In Thunderbird 3.0b, you do that as follows: Tools | Message Filters Make sure the correct account is selected. Click "New" Conditions: Body contains places-to-b-and-h Change the action to "Delete Message". Select "Manually Run" from the dropdown at the top. Click OK. Select the filter in the list, make sure "Inbox" is selected at the bottom, and click "Run Now". This should delete all the bugspam. You can then delete the filter. Gerv

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.