Missing window icon on Wayland
New one for the window icon issue mentioned in #80
On wayland, while the overview shows the zathura icon in the list of applications, when switching open windows etc., zathura's icon is not shown. Instead a generic "missing icon" icon is used.
This is what I got from the gnome discourse thread where I asked for help: https://discourse.gnome.org/t/help-debugging-zathura-window-title-issue/1450/4
Wayland doesn’t have a concept of window icons, so gtk_window_set_icon_*() are not implemented in the gdk wayland backend.
The icon in the window switcher comes from the .desktop file, which means that gnome-shell must be able to match the window to the application. This requires setting the application id to match the .desktop file. The best way to do this is with GtkApplication and either GtkApplicationWindow or gtk_window_set_application(), but you can fix this minimally with:
g_set_prgname("org.pwmt.zathura");
For historical reasons, this call is recommended for GTK 3 1 even if you do use GtkApplication. Otherwise, the xdg-shell app_id will not match.
Seems like a simple enough fix, although I'll have to check if this should be made in girara or zathura. I think this will also fix the issue where multiple Zathura windows were not being grouped as a single application.