User Agent: Mozilla/5.0 (X11; Linux i686; rv:25.0) Gecko/20100101 Firefox/25.0 (Beta/Release) Build ID: 20131030131604 Steps to reproduce: I have a bookmark on my "Bookmarks Toolbar" that has the url "about:blank". I use it when I am finished viewing a page and wish to blank the browser window. The toolbar favicon is a "blank page" icon (or something). I open a URL in a tab and then I open a second tab. Both tabs have a favicon displayed I drag the second tab off into the root window in order to have it in a second FF window instead of a tab in the first window. As soon as this is done, the favicon for my "blank window" toolbar bookmark is been set to the favicon of the window that was dragged. Actual results: The toolbar bookmark icon is changed to an in appropriate favicon Expected results: The favicon for my "blank" toolbar bookmark should have been unchanged.

Regression window(m-c) Gooed: http://hg.mozilla.org/mozilla-central/rev/9805493631d4 Mozilla/5.0 (Windows; Windows NT 6.1; WOW64; rv:2.0b3pre) Gecko/20100722 Minefield/4.0b3pre ID:20100722041409 Bad: http://hg.mozilla.org/mozilla-central/rev/dfaba4e449bd Mozilla/5.0 (Windows; Windows NT 6.1; WOW64; rv:2.0b3pre) Gecko/20100722 Minefield/4.0b3pre ID:20100722083711 Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9805493631d4&tochange=dfaba4e449bd Regressed by: 87fddd376838 Marco Bonardo — Bug 499828 - kill LAZY_ADD and use async storage instead. r=sdwilsh

I was hoping this bug entered 4 YEARS AGO might have been fixed with 57 and later, but it still apparently has not. I'm now running FF 58.0 and a tab which I keep in the tab bar to create a blank screen (new tab) now has its icon set to the Facebook icon. Used to be I could scrounge around in the sqlite database, find the appropriate spot and fix it, but with 57 and later, I don't have that ability. Is there any chance this can be fixed some day?

I doubt your bug is the same as this one, that I should really resolve since it's too old to figure out anything. What you see is likely bug 1428751.