twitter/bootstrap — pull request #4591 by jpadvo (2012-08-22 18:21:38+00:00)
Title: Fix left-side-cutoff problem with prepended inputs in togglable tabs

When a prepended input is inside of a togglable tab, the left border gets cut off; see this fiddle:

http://jsfiddle.net/RyesV/

To fix it I simply (naively) added `1px` of margin to the left side of prepended inputs if they are inside a `.tab-content` element. Seems to work.