The bookmarks toolbar items are not displayed by default

The bookmarks toolbar items are not displayed by default, even if the bookmarks toolbar is.

to reproduce :

• install a pristine Tor Browser (I tried on Debian)
• opt-in to display the "Bookmarks Toolbar" (Library → Bookmarks → Bookmarking Tools → View Bookmarks Toolbar)
• add a bookmark in that toolbar

result: the bookmarks toolbar is empty

to solve the issue, one need to right-click on the toolbar, click "Customize", and drag'n'drop "Bookmarks Toolbar Items" to the toolbar.

note that it also affects all Tails users (https://labs.riseup.net/code/issues/15935).

Trac:
Username: goupille