Cannot add okular to favorites in the dock

[Simon May]

1) Ubuntu version: 19.10

2) Package version: okular 4:19.04.3-0ubuntu1 (APT package)

3) What you expected to happen:
When starting okular, its icon appears in the dock (as for any other program). When right-clicking this icon, the option “Add to Favorites” should appear, which allows one to pin the program to the dock so that it can be launched from there.

4) What happened instead:
The option “Add to Favorites” is missing for the okular icon. This can be fixed by adding the line

StartupWMClass=okular

to the file “/usr/share/applications/org.kde.okular.desktop”.