Revert "MainWindow: Better detect when running in live session (#733)" (

#736)

This reverts commit c4c9e69.

src/MainWindow.vala

@@ -36,29 +36,7 @@ public class Greeter.MainWindow : Gtk.ApplicationWindow {
     private int current_user_card_index = 0;
     private unowned Greeter.BaseCard? current_card = null;
 
-    private bool? _is_live_session = null;
-    private bool is_live_session {
-        get {
-            if (_is_live_session != null) {
-                return _is_live_session;
-            }
-
-            _is_live_session = false;
-
-            var proc_cmdline = File.new_for_path ("/proc/cmdline");
-            try {
-                var dis = new DataInputStream (proc_cmdline.read ());
-                var line = dis.read_line ();
-                if ("boot=casper" in line || "boot=live" in line || "rd.live.image" in line) {
-                    _is_live_session = true;
-                }
-            } catch (Error e) {
-                critical ("Couldn't detect if running in Live Session: %s", e.message);
-            }
-
-            return _is_live_session;
-        }
-    }
+    private bool installer_mode = false;
 
     private Gtk.EventControllerKey key_controller;
 
@@ -408,7 +386,7 @@ public class Greeter.MainWindow : Gtk.ApplicationWindow {
 
                 // If the greeter is running on the install medium, check if the Installer has signalled
                 // that it wants the greeter to launch the live (demo) session by means of touching a file
-                if (is_live_session) {
+                if (installer_mode) {
                     var demo_mode_file = File.new_for_path ("/var/lib/lightdm/demo-mode");
                     if (demo_mode_file.query_exists ()) {
                         demo_mode_file.@delete ();
@@ -453,15 +431,19 @@ public class Greeter.MainWindow : Gtk.ApplicationWindow {
             critical (e.message);
         }
 
-        // Don't need to build user cards etc in live media
-        if (is_live_session) {
-            return;
-        }
+        lightdm_greeter.notify_property ("show-manual-login-hint");
+        lightdm_greeter.notify_property ("has-guest-account-hint");
 
         if (lightdm_greeter.default_session_hint != null) {
             get_action_group ("session").activate_action ("select", new GLib.Variant.string (lightdm_greeter.default_session_hint));
         }
 
+        // Check if the installer is installed
+        var installer_desktop = new DesktopAppInfo ("io.elementary.installer.desktop");
+        if (installer_desktop != null) {
+            installer_mode = true;
+        }
+
         if (lightdm_user_list.length > 0) {
             datetime_revealer.reveal_child = true;
 
@@ -515,8 +497,6 @@ public class Greeter.MainWindow : Gtk.ApplicationWindow {
         }
 
         lightdm_greeter.notify_property ("hide-users-hint");
-        lightdm_greeter.notify_property ("show-manual-login-hint");
-        lightdm_greeter.notify_property ("has-guest-account-hint");
     }
 
     private void add_card (LightDM.User lightdm_user) {