Broken ligatures in recent LilyPond versions

[Noeck]

Hi,

LilyPond used to do ligatures correctly in 2.16.2 (see image). In 2.18.2 and
2.19 versions, the ligatures are broken. Why?

System: Ubuntu (Linux)
2.16.2 installed via system packages
2.18.2 and above installed using the sh script from the webpage

Snippet:

\paper {
  fonts = #
  (make-pango-font-tree
   "Linux Libertine O"
   "Linux Biolinum O"
   "Ubuntu Mono"
   (/ (* staff-height pt) 2.5))
}

\markup "Ligatures: The Que fi fl"

Cheers,
Joram

ligatures-2-16.png
Description: PNG image

ligatures-2-18.png
Description: PNG image