Doesn't reproduce spacing between letters properly
Testcase: download the pdf from here ("save" function): http://sci-hub.tw/10.1021/cr980401l#
Please observe how these letter combinations have too small space, and run on each other: "ch", "es", "ea".
The chrome browser doesn't have this problem.
OS: FreeBSD 11.2
poppler-0.57.0_1
Okular version: 1.5.0
The original okular bug report: https://bugs.kde.org/show_bug.cgi?id=397902