STR: Go to Firefox labs in about:preferences. Select and unselect "sidebar" a few times. Go to View > Sidebar in your OS. You should see the the sidebar options duplicate every time "sidebar" is selected.
Bug 1915007 Comment 0 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
STR: Go to Firefox labs in about:preferences. Select and unselect "sidebar" a few times. Go to View > Sidebar in your OS. You should see that the sidebar options duplicate every time "sidebar" is selected.