[tex-live] xdvipdfmx: tounicode entries for ligatures missing in pdf

[Ulrike Fischer]

on tex.sx there is a question about a failing search in pdf
https://tex.stackexchange.com/questions/430054/failing-search-for-words-with-ligatures-after-update

As I happened to have the font available I tested and can confirm
that something changed between TL17 and TL18:

\documentclass{book}

\usepackage{fontspec}
\setmainfont{FrutigerLTCom-Light.ttf}
\begin{document}
Prefix.
\end{document}

With xelatex in TL17 is works fine and one can search in the pdf for
"Prefix", in TL18 it not longer works.

The fonts are the same but in the newer pdf a mapping for the
ligature is missing:

7 beginbfchar
<0011> <002E>
<0014> <0031>
<0033> <0050>
<0048> <0065>
<0055> <0072>
<005B> <0078>
<011F> <FB01>  %<------- missing in TL18
endbfchar
 
Another (free) font with the same Problem is Roboto:

\setmainfont{Roboto-Regular.ttf} leads to

7 beginbfchar
<0012> <002E>
<0015> <0031>
<0034> <0050>
<0049> <0065>
<0056> <0072>
<005C> <0078>
<01A4> <FB01> %<--- missing in TL18
endbfchar

(But here the fonts are perhaps not identical as they are in the
texmf trees).

-- 
Ulrike Fischer 
http://www.troubleshooting-tex.de/