Bug in whichBar?

[Trevor Daniels]

There seems to be a bug in \set whichBar.  Rather than setting the type of 
barline to print at the end of the bars it prints a barline after every 
following note.  Surely this isn't correct?  Here's a short example:

\version "2.11.44"
\relative c' {
 d d d d
 \set Staff.whichBar = "||"
 e8 e e e
 \unset Staff.whichBar
 f f f f
}