.dl-horizontal with empty <dd> is not working

Created by: dairiki

The &:extend(.clearfix all) on .dl-horizontal dd (line 209 of type.less) does not seem to be working. I.e. the dds are not getting clearfixed, with the result that if a <dd> is empty, the <dd>s from the subsequent row will move up, being displayed in place of the empty <dd>.

This appears to have become an issue with 3.1.0 when .clearfix() was replaced with &:extend(.clearfix all) (in 0016c17f). (Perhaps this, at its root, is a lessc bug having to do with extends within media queries?)

A demo of the problem is at http://jsbin.com/codam/1. (Note that bar def should be displayed on the same "row" as Bar, but instead it is displayed next to Foo.)

Updated: Fixed link to commit 0016c17f