Force text on line without using \textLengthOn

[Urs Liska]

Hi,

I want to use TextScript.staff-padding to produce markup elements that 
are aligned to their baseline. In order to prevent the texts from moving 
vertically to avoid collisions I used \textLengthOn (or its spelled-out 
variant):

\version "2.19.82"

test =
#(define-event-function (text)(markup?)
   #{
     -\tweak extra-spacing-width #(cons -0.0 0.4)
     -\tweak extra-spacing-height #(cons -inf.0 +inf.0)
     -\tweak staff-padding 3
     -\markup #text
   #})

\relative {
  c''8 ^\test "foobar" d16 c
  c8 ^\test "foobar" d16 ^\test "John Doe" c
}

However, this does not only push the next notes when there actually is 
some neighboring text (as in the second beat of the following example) 
but also when it wouldn't be needed (see atttached image):

Uncommenting the extra-spacing... tweaks will result in the texts moving 
vertically which is not desired.

Is there another approach to make the following note columns move - but 
only if there *is* something in the way?

Thanks
Urs

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