[Affected versions]: Nightly 55.0a1 [Affected platforms]: Platforms: Windows 10 x 64, Ubuntu 16.04 x64 and Mac OS X 10.12 [Steps to reproduce]: 1. You should have 2 Firefox profiles with different bookmarks and history. 2. Launch Firefox with your first Firefox account. 3. Click on "Show your bookmarks" near search bar. 4. Click on "Show All bookmarks". 5. Click on "Import and Backup" and then click on "Export Bookmarks to HTML" and save the bookmarks. 6. Launch Firefox with your second Firefox account. 7. Click on "Show your bookmarks" near search bar. 8. Click on "Show All bookmarks". 9. Click on "Import and Backup" and then click on "Import Bookmarks to HTML" and choose the bookmarks that you want to import. [Expected result]: All bookmarks in library, bookmarks list, menu bar and in bookmarks toolbar are correctly displayed. [Actual result]: Not all bookmarks in library, bookmarks list, menu bar and in bookmarks toolbar are correctly displayed.

html exports are obsolete, we support them for legacy reasons, but they are not a primary target. Favicons are still exported in html files BUT they have space for only one favicon and new favicons can be more than one per page. When possible we try to export a single icon, but in many cases it's no more possible. In practice we can't make any promise related to exporting favicons to html, it may work or not depending on the page. There may be some space for improvements, but this is far from being a priority.