> It would be easy to only exempt Null-Principaled about: documents, but I am not certain you can't create a popup with a null principal sandboxed iframe, http://mozilla.pettay.fi/moztests/sandbox_aboutblank_popup.html
Bug 1830070 Comment 17 Edit History
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> It would be easy to only exempt Null-Principaled about: documents, but I am not certain you can't create a popup with a null principal sandboxed iframe, http://mozilla.pettay.fi/moztests/sandbox_aboutblank_popup.html Edit: I guess one of the tests is doing that.