User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/20100101 Firefox/16.0 Build ID: 20121024073032 Steps to reproduce: I'm developing an add-on (OmniSidebar), one of the features of which is to add a toolbar to the sidebar header. This is just like any other toolbar and while adjusting a few details to ensure proper display under all customize settings, when I tried the "Icons and Text" setting I found all the buttons took the width of 57px, regardless if this would hide the button labels. There is no special CSS code being set in these buttons or the toolbar itself, other than a few margins and paddings and borders, but even to test it I tried removing it all, essentially just leaving the toolbar itself with the buttons. I've attached a screenshot of this. I've confirmed this on versions 16 through 19 (Nightly), but I remember this behavior going back as maybe Firefox 7 or 8. Actual results: Buttons in the navigation toolbar resize as expected when the label is too big, but the buttons in my custom toolbars stay at the 57px mark, cropping the labels. No matter what I do, even forcibly setting their width to whatever value, they will always keep the 57px size. This is because of chrome://browser/skin/browser.css line 552 (at least in Aurora 18.0a2): toolbar[mode=full] .toolbarbutton-1, toolbar[mode=full] .toolbarbutton-1 > .toolbarbutton-menubutton-button { min-width: 57px; } In fact, if I change the 'min-width' value then the buttons will acquire the new 'min-width', apparently interpreting it as 'width'. Expected results: The buttons should behave as if in any other toolbar, increasing their width if necessary when they have longer labels. Short of removing the .toolbarbutton-1 class and setting all its derived properties manually except for the min-width, which of course I don't want to do, I haven't managed any solution to get the buttons to behave as they should.

Can you attach please the version of add-on in which you reproduced the bug?

You'll have to enable the add-on, add some buttons to the sidebar toolbar and change the show option to icons and text (and of course open the sidebar to actually see it)

No longer an issue with Australis. I'm going ahead and close it now as it's a very specific issue and unlikely to be of any bother for the remainder of the time until Australis hits release.