Yes, this can still be reproduced. If I load testcase 1 in current Nightly 98.0a1 (2022-01-13) and inspect with a zoom tool (e.g. the Gnome Accessibility "Zoom" Feature, or take a screenshot and zoom in in a graphics editor), then it's clear that there are reddish pixels outside the white border, as shown in comment 3.
Bug 1473083 Comment 19 Edit History
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Yes, this can still be reproduced. If I load testcase 1 in current Nightly 98.0a1 (2022-01-13) and inspect with a zoom tool (e.g. the Gnome Accessibility "Zoom" Feature, or take a screenshot and zoom in in a graphics editor), then it's clear that there are reddish pixels outside the white border, as shown in comment 3. (While I'm here, I'll drop the mention of Google Inbox from the bug summary, since that product no longer exists.)