Endless Loop

[Jay Anderson]

Compiling this score (reduced from a larger score) never terminates:
=================
\version "2.15.30"

\score
{
  \new Staff \relative c'
  {
    R1 |
    \stopStaff
    R1 | r2
  }
}
=================

If I'm stopping the staff I should probably be using spacer rests
instead and this problem goes away. So I finally figured that out, but
I would expect some sort of warning or error instead of an infinite
loop.

I traced this to this commit:
=================
$ git bisect bad
3d8f4559228bd8a4a30bb024163b64d425b76f18 is the first bad commit
commit 3d8f4559228bd8a4a30bb024163b64d425b76f18
Author: Benkő Pál <address@hidden>
Date:   Mon Feb 13 18:49:17 2012 +0100

    Issue 2300: do not tinker with the position of a pitched rest
=================

It seems to be stuck in this loop (rest.cc, line 78):

      /*
        make sure rest is aligned to a staff line
      */
      while (!Staff_symbol_referencer::on_line (me, pos))
        ++pos;

-----Jay