I#1620 - Flatpak: Set StartupWMClass in the .desktop file

Closes https://gitlab.gnome.org/GNOME/evolution/-/issues/1620

data/CMakeLists.txt

@@ -1,6 +1,14 @@
 set(filedeps)
 set(desktopdir ${SHARE_INSTALL_PREFIX}/applications)
 
+option(WITH_WMCLASS_OVERRIDE "Override WMClass in the .desktop file" "")
+
+if("${WITH_WMCLASS_OVERRIDE}" STREQUAL "" OR "${WITH_WMCLASS_OVERRIDE}" STREQUAL "OFF")
+	set(WMCLASS_OVERRIDE "")
+else("${WITH_WMCLASS_OVERRIDE}" STREQUAL "" OR "${WITH_WMCLASS_OVERRIDE}" STREQUAL "OFF")
+	set(WMCLASS_OVERRIDE "StartupWMClass=${WITH_WMCLASS_OVERRIDE}\n")
+endif("${WITH_WMCLASS_OVERRIDE}" STREQUAL "" OR "${WITH_WMCLASS_OVERRIDE}" STREQUAL "OFF")
+
 configure_file(org.gnome.Evolution.desktop.in.in
 	org.gnome.Evolution.desktop.in
 	@ONLY

data/org.gnome.Evolution.desktop.in.in

@@ -19,7 +19,7 @@ X-GNOME-Bugzilla-OtherBinaries=evolution-addressbook-factory;evolution-calendar-
 X-GNOME-UsesNotifications=true
 X-Flatpak-RenamedFrom=evolution
 MimeType=text/calendar;text/x-vcard;text/directory;application/mbox;message/rfc822;x-scheme-handler/mailto;x-scheme-handler/webcal;x-scheme-handler/calendar;x-scheme-handler/task;x-scheme-handler/memo;
-
+@WMCLASS_OVERRIDE@
 [Desktop Action new-window]
 _Name=New Window
 Exec=evolution -c current

flatpak/org.gnome.Evolution-master.json

@@ -329,7 +329,8 @@
 				"-DENABLE_YTNEF=OFF",
 				"-DWITH_BOGOFILTER=/app/bin/bogofilter",
 				"-DWITH_GLADE_CATALOG=OFF",
-				"-DWITH_HELP=OFF"
+				"-DWITH_HELP=OFF",
+				"-DWITH_WMCLASS_OVERRIDE=evolution.bin"
 			],
 			"cleanup": [
 				"/etc/xdg",