The auto-created bookmark button seems to work fine if the personal-bookmark widget is on the bookmark toolbar. 1. bookmark widget on visible bookmark bar with a visible menu bar = NO bookmark button! open a new window = NO bookmark button! restarted browser new window = NO bookmark button! hide and reshow menu bar = NO bookmark button! hide and reshow bookmark bar = NO bookmark button! 2. bookmark widget on hidden bookmark bar with a visible menu bar = NO bookmark button! open a new window = NO bookmark button! restarted browser new window = NO bookmark button! hide and reshow menu bar = NO bookmark button! reshow and hide bookmark bar = NO bookmark button! 3. bookmark widget on visible bookmark bar with a hidden menu bar = bookmark button on bookmark bar open a new window = bookmark button on bookmark bar restarted browser new window = bookmark button on bookmark bar reshow and hide menu bar = bookmark button on bookmark bar hide and reshow bookmark bar = bookmark button on bookmark bar 4. bookmark widget on hidden bookmark bar with a hidden menu bar = bookmark button on navigation bar open a new window = bookmark button on navigation bar restarted browser new window = bookmark button on navigation bar reshow and hide menu bar = bookmark button on navigation bar* reshow and hide bookmark bar = bookmark button on navigation bar (*) bookmark button disappears while menu is visible However, I've placed the personal-bookmark widget on the MENU bar for easy recall and dismissal with the ALT key. With the widget on the menubar, all hell breaks loose and there is no telling where the bookmark button will or will not pop up next especially on new windows or after a restart. 5. with a visible bookmark bar bookmark widget on visible menu bar = bookmark button on menu bar open a new window = NO bookmark button! restarted browser new window = NO bookmark button! hide and reshow menu bar = bookmark button on menu bar hide and reshow bookmark bar = bookmark button on menu bar 6. with a hidden bookmark bar bookmark widget on visible menu bar = bookmark button on menu bar open a new window = NO bookmark button! restarted browser new window = NO bookmark button! hide and reshow menu bar = bookmark button on menu bar reshow and hide bookmark bar = bookmark button on menu bar 7. with a visible bookmark bar bookmark widget on hidden menu bar = NO bookmark button! open a new window = bookmark button on navigation bar restarted browser new window = bookmark button on navigation bar reshow and hide menu bar = NO bookmark button! hide and reshow bookmark bar = NO bookmark button! 8. with a hidden bookmark bar bookmark widget on hidden menu bar = NO bookmark button! open a new window = bookmark button on navigation bar restarted browser new window = bookmark button on navigation bar reshow and hide menu bar = NO bookmark button! reshow and hide bookmark bar = NO bookmark button! What ultimately is or is not proper behaviour is up to the developers to decide but as it stands now this user does not think the above is correct and certainly not what I would expect.

looks like moving Bookmarks Toolbar Items to menubar it loses the flex, when we run check at startup the element has width 0, while it should take all avail space.

part of the problem is this missing selector

the other part of the problem is that button is moved to menubar that has autohide = true, thus when we check if element is visible that toolbar could be hidden and the element not visible.

I can probably handle comment 3 in bug 575218 with a different visibility check.

this hides the button if the menubar is not autohide (I did not want to add crazy checks to handle any edge-case, since request is to hide it, just hide it) http://hg.mozilla.org/mozilla-central/rev/fa7b6f39faf4