This is quick and dirty, but not correct.
Now the button-toolbar is expanded, too. "font-size: 0" isn't there for nothing, NOT A BUG.

We are in the class .btn-toolbar context, here.
The new context is already set via class ".dropdown-menu", so we need a font-size reset there.

A) By applying the existing ".nav-list" class to the current <li> element
and adding the "font-size: 13px" in css there like in ".nav-header". (affecting template.css)

B) .. or by applying a new reset class like <ul class="dropdown-menu dropdown-btn-toolbar">
and doing it there. (not affecting template.css)

This is what I would suggest, or is there already a class for doing that in template.css?

Hi,
Your suggestion B) would mean to change the file yoursite/libraries/cms/cck/dev/integration.php at line 112 for example: $html =   '<ul class="dropdown-menu" style="font-size:13px;">' or what class you could use here?

I have the css file again checked - # ffff, I have probably produced this bug myself ​​- sorry.

kind regards

Castor

Good idea.

Here is what I found to work the easiest, added to template.css or your own cascade:

.btn-toolbar .dropdown-menu {font-size: 13px;}

Thumbs up,

I have added

.btn-toolbar .dropdown-menu {font-size: 13px;}

at the end of the template 

yoursite/administrator/components/com_cck/assets/css/admin.css

kind regards

Thanks a lot, Castor, for your solution adding .btn-toolbar .dropdown-menu {font-size: 13px;} to admin.css!

I had this problem for the third time now, not finding the solution by myself, always resulting in a new installation.

You saved my weekend! Thank you.