xsession: cleanup systemd variables (#3636)

modules/xsession.nix

@@ -78,6 +78,7 @@ in {
 
       importedVariables = mkOption {
         type = types.listOf (types.strMatching "[a-zA-Z_][a-zA-Z0-9_]*");
+        apply = unique;
         example = [ "GDK_PIXBUF_ICON_LOADER" ];
         visible = false;
         description = ''
@@ -184,7 +185,7 @@ in {
 
       ${optionalString (cfg.importedVariables != [ ])
       ("systemctl --user import-environment "
-        + toString (unique cfg.importedVariables))}
+        + escapeShellArgs cfg.importedVariables)}
 
       ${cfg.profileExtra}
 
@@ -212,6 +213,10 @@ in {
         while [ -n "$(systemctl --user --no-legend --state=deactivating list-units)" ]; do
           sleep 0.5
         done
+
+        ${optionalString (cfg.importedVariables != [ ])
+        ("systemctl --user unset-environment "
+          + escapeShellArgs cfg.importedVariables)}
       '';
     };
   };

tests/modules/misc/xsession/basic-xprofile-expected.txt

@@ -9,7 +9,7 @@ fi
 # script starts up graphical-session.target.
 systemctl --user stop graphical-session.target graphical-session-pre.target
 
-systemctl --user import-environment DBUS_SESSION_BUS_ADDRESS DISPLAY SSH_AUTH_SOCK XAUTHORITY XDG_DATA_DIRS XDG_RUNTIME_DIR XDG_SESSION_ID EXTRA_IMPORTED_VARIABLE
+systemctl --user import-environment 'DBUS_SESSION_BUS_ADDRESS' 'DISPLAY' 'SSH_AUTH_SOCK' 'XAUTHORITY' 'XDG_DATA_DIRS' 'XDG_RUNTIME_DIR' 'XDG_SESSION_ID' 'EXTRA_IMPORTED_VARIABLE'
 
 profile extra commands
 

tests/modules/misc/xsession/basic-xsession-expected.txt

@@ -16,3 +16,5 @@ systemctl --user stop graphical-session-pre.target
 while [ -n "$(systemctl --user --no-legend --state=deactivating list-units)" ]; do
   sleep 0.5
 done
+
+systemctl --user unset-environment 'DBUS_SESSION_BUS_ADDRESS' 'DISPLAY' 'SSH_AUTH_SOCK' 'XAUTHORITY' 'XDG_DATA_DIRS' 'XDG_RUNTIME_DIR' 'XDG_SESSION_ID' 'EXTRA_IMPORTED_VARIABLE'