Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:59.0) Gecko/20100101 Firefox/59.0 ID:20171222220251 Steps to reproduce: 1. Launch Nightly 2. Open a new tab if there is no new tab (about:newtab) 3. Right click on a new tab and select "Duplicate Tab" in context menus Actual results: No favicon in a new tab created using Duplicate Tab. Expected results: New tab have favicon even if using Duplicate Tab. Regression range: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=1dfa2eb559ad896115dcd9ee13f63da6ed1fce18&tochange=28f5404cc95e8e911bb21545b73638473b4aecd9

johannh, looks like removing the favicon from the page is causing various issues like this one for duplicating tabs, and bug 1423256 for restoring tabs, and bug 1422962 for new windows. Do we want to be special casing all of these places with the chrome provided favicon instead of having content suggest one with <link rel=icon>?

(In reply to Ed Lee :Mardak from comment #1) > johannh, looks like removing the favicon from the page is causing various > issues like this one for duplicating tabs, and bug 1423256 for restoring > tabs, and bug 1422962 for new windows. Do we want to be special casing all > of these places with the chrome provided favicon instead of having content > suggest one with <link rel=icon>? Bug 1422962 is not caused by removing the favicon. We want to special case common pages like about:home, about:newtab and about:privatebrowsing but to avoid these other edge cases we could consider adding the <link rel=icon> back to the pages, as long as we know that it isn't re-introducing flicker in the common case.

I have verified this bug was resolved by bug 1423256.

Thanks!