Rests display error in single-staff polyphony

[Albert Frantz]

Hello,

I believe I've just uncovered a bug when displaying rests in measures with
single-staff polyphony (version 2.8.2).  As a small example:

<< { f2( e4) h4\rest } \\ { d2 c4 } >>

Since there's only one rest, it should be centered on the staff; using r4 does
not automatically accomplish this (as it should!).

Therefore, I've tried manually adjusting the rest location using h4\rest as
mentioned in the manual. Strangely, every pitch other than h or b (using
\include "deutsch.ly") moves the rest properly.

I request that this apparent bug be fixed, and equally importantly, for rests
(e.g. r4) in single-staff polyphony to be centered vertically rather than offset
when the other voice is empty, as very often occurs.


Many thanks,

Albert