#5542 cross-staff slur hides text in eps backend

[Werner LEMBERG]

[git version from today]

\version "2.21.0"

\header {
  texidoc = "
Cross-staff slurs must behave the same in the eps
backend.

Here is a counterexample; the string `foo' located
right over the last note completely disappears.  In
other words, this is a more serious cropping issue
than inaccurate bounding boxes.
"
}

%#(ly:set-option 'backend 'eps)

\header {
  copyright = ""
  tagline = ##f
}

<< \new Staff = "A" {
     g4 g'' \change Staff = "B" g(
            \change Staff = "A" g'')^"foo" }
   \new Staff = "B" { s1 } >>

[Valentin Villenave]

It’s even worse, it seems: as soon as there’s a cross-staff slur, nothing else (scripts, markups, whatever) can be encompassed in the skylines:

%#(ly:set-option 'backend 'eps)
#(ly:set-option 'debug-skylines)
\header { tagline=##f }

<< \new Staff = "A" {
  g4(_\fermata g'')\fermata
  \change Staff = "B" g(_\fermata
  \change Staff = "A" g'')\fermata }
   \new Staff = "B" { s1 } >>