#5313 Slur doesn't avoid the trill spanner

%%% Start
\version "2.19.81"
\language "english"

{
\override TrillSpanner.avoid-slur = #'inside
\override TrillSpanner.outside-staff-priority = ##f
c''1( | c''2. \startTrillSpan c''4 \stopTrillSpan | c''1) |
}
%%% End

...the slur doesn't avoid the trill spanner.

[Anonymous]

Just to add this is the same output when run using 2.18.2