Manual beaming over rests and vertical spacing problem

[Clément]

> I'm not top posting.

Hello,

Using oneVoice position (or indirectly, partcombineApart) while making a beam 
go 
over a rest destroys vertical alignment in a staff.

Here is a small example, with or without manual beaming over the rest.

%%%

\version "2.17.13"

\relative c'' {
  \voiceOne \dynamicUp f4\fz f8 f f[ r16 f] f8 f |
  \override DynamicText #'X-offset = #-3 f4\fz f8 f f[ r16 f] f8 f | \mark 
\default
}

\relative c'' {
  \voiceOne \dynamicUp f4\fz f8 f f r16 f f8 f |
  \override DynamicText #'X-offset = #-3 f4\fz f8 f f r16 f f8 f | \mark 
\default
}

%%%

Overriding outside-staff-priority or Y-offset is uneffective.
It also affects BarNumber's vertical position.

I encountered this bug while updating a score from an older version of 
lilypond, 
but I cannot remember which one exactly. I think it was 2.16.